1620694656 has 320 divisors, whose sum is σ = 5586482880. Its totient is φ = 456855552.

The previous prime is 1620694637. The next prime is 1620694657. The reversal of 1620694656 is 6564960261.

It is a super-3 number, since 3×1620694656³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1620694657) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 9942831 + ... + 9942993.

It is an arithmetic number, because the mean of its divisors is an integer number (17457759).

Almost surely, 2^1620694656 is an apocalyptic number.

1620694656 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 1620694656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2793241440).

1620694656 is an abundant number, since it is smaller than the sum of its proper divisors (3965788224).

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

1620694656 is a wasteful number, since it uses less digits than its factorization.

1620694656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333 (or 312 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The square root of 1620694656 is about 40257.8521036580. The cubic root of 1620694656 is about 1174.6281378867.

The spelling of 1620694656 in words is "one billion, six hundred twenty million, six hundred ninety-four thousand, six hundred fifty-six".