551721556 has 12 divisors (see below), whose sum is σ = 965811168. Its totient is φ = 275775512.

The previous prime is 551721473. The next prime is 551721557. The reversal of 551721556 is 655127155.

It is a super-2 number, since 2×551721556² = 608793350710122272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (551721557) 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, 5446 + ... + 33661.

It is an arithmetic number, because the mean of its divisors is an integer number (80484264).

Almost surely, 2^551721556 is an apocalyptic number.

It is an amenable number.

551721556 is a deficient number, since it is larger than the sum of its proper divisors (414089612).

551721556 is a wasteful number, since it uses less digits than its factorization.

551721556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42638 (or 42636 counting only the distinct ones).

The product of its digits is 52500, while the sum is 37.

The square root of 551721556 is about 23488.7538196474. The cubic root of 551721556 is about 820.1752332224.

The spelling of 551721556 in words is "five hundred fifty-one million, seven hundred twenty-one thousand, five hundred fifty-six".