556689621 has 4 divisors (see below), whose sum is σ = 742252832. Its totient is φ = 371126412.

The previous prime is 556689613. The next prime is 556689643. The reversal of 556689621 is 126986655.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 556689621 - 2³ = 556689613 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (556689691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92781601 + ... + 92781606.

It is an arithmetic number, because the mean of its divisors is an integer number (185563208).

Almost surely, 2^556689621 is an apocalyptic number.

It is an amenable number.

556689621 is a deficient number, since it is larger than the sum of its proper divisors (185563211).

556689621 is a wasteful number, since it uses less digits than its factorization.

556689621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185563210.

The product of its digits is 777600, while the sum is 48.

The square root of 556689621 is about 23594.2709359709. The cubic root of 556689621 is about 822.6296804362.

The spelling of 556689621 in words is "five hundred fifty-six million, six hundred eighty-nine thousand, six hundred twenty-one".