1621562880 has 480 divisors, whose sum is σ = 6269598720. Its totient is φ = 356106240.

The previous prime is 1621562879. The next prime is 1621562881. The reversal of 1621562880 is 882651261.

It is an interprime number because it is at equal distance from previous prime (1621562879) and next prime (1621562881).

It is a tau number, because it is divible by the number of its divisors (480).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621562881) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11665851 + ... + 11665989.

It is an arithmetic number, because the mean of its divisors is an integer number (13061664).

Almost surely, 2^1621562880 is an apocalyptic number.

1621562880 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 1621562880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3134799360).

1621562880 is an abundant number, since it is smaller than the sum of its proper divisors (4648035840).

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

1621562880 is a wasteful number, since it uses less digits than its factorization.

1621562880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210 (or 187 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 39.

The square root of 1621562880 is about 40268.6339475279. The cubic root of 1621562880 is about 1174.8378541911.

The spelling of 1621562880 in words is "one billion, six hundred twenty-one million, five hundred sixty-two thousand, eight hundred eighty".