1620256404 has 36 divisors (see below), whose sum is σ = 4093789056. Its totient is φ = 498539808.

The previous prime is 1620256373. The next prime is 1620256411. The reversal of 1620256404 is 4046520261.

It is a super-2 number, since 2×1620256404² = 5250461629406022432, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 397444 + ... + 401499.

Almost surely, 2^1620256404 is an apocalyptic number.

It is an amenable number.

1620256404 is an abundant number, since it is smaller than the sum of its proper divisors (2473532652).

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

1620256404 is a wasteful number, since it uses less digits than its factorization.

1620256404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798976 (or 798961 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 1620256404 is about 40252.4086732707. The cubic root of 1620256404 is about 1174.5222512870.

Adding to 1620256404 its reverse (4046520261), we get a palindrome (5666776665).

The spelling of 1620256404 in words is "one billion, six hundred twenty million, two hundred fifty-six thousand, four hundred four".