1620311616 has 504 divisors, whose sum is σ = 6260750496. Its totient is φ = 394813440.

The previous prime is 1620311611. The next prime is 1620311617. The reversal of 1620311616 is 6161130261.

1620311616 is a `hidden beast` number, since 1 + 620 + 31 + 1 + 6 + 1 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (504).

It is a self number, because there is not a number n which added to its sum of digits gives 1620311616.

It is not an unprimeable number, because it can be changed into a prime (1620311611) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 5277735 + ... + 5278041.

It is an arithmetic number, because the mean of its divisors is an integer number (12422124).

Almost surely, 2^1620311616 is an apocalyptic number.

1620311616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1620311616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3130375248).

1620311616 is an abundant number, since it is smaller than the sum of its proper divisors (4640438880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1620311616 is a wasteful number, since it uses less digits than its factorization.

1620311616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367 (or 347 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 1620311616 is about 40253.0944897408. The cubic root of 1620311616 is about 1174.5355921768.

Adding to 1620311616 its reverse (6161130261), we get a palindrome (7781441877).

It can be divided in two parts, 1620 and 311616, that added together give a triangular number (313236 = T₇₉₁).

The spelling of 1620311616 in words is "one billion, six hundred twenty million, three hundred eleven thousand, six hundred sixteen".