1620216620 has 72 divisors (see below), whose sum is σ = 3959982432. Its totient is φ = 554498560.

The previous prime is 1620216617. The next prime is 1620216629. The reversal of 1620216620 is 266120261.

It is a self number, because there is not a number n which added to its sum of digits gives 1620216620.

It is not an unprimeable number, because it can be changed into a prime (1620216629) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21449 + ... + 60831.

It is an arithmetic number, because the mean of its divisors is an integer number (54999756).

Almost surely, 2^1620216620 is an apocalyptic number.

1620216620 is a gapful number since it is divisible by the number (10) 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 1620216620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1979991216).

1620216620 is an abundant number, since it is smaller than the sum of its proper divisors (2339765812).

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

1620216620 is a wasteful number, since it uses less digits than its factorization.

1620216620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39431 (or 39418 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 1620216620 is about 40251.9144886302. The cubic root of 1620216620 is about 1174.5126380811.

Adding to 1620216620 its reverse (266120261), we get a palindrome (1886336881).

The spelling of 1620216620 in words is "one billion, six hundred twenty million, two hundred sixteen thousand, six hundred twenty".