551321604 has 18 divisors (see below), whose sum is σ = 1393618590. Its totient is φ = 183773856.

The previous prime is 551321593. The next prime is 551321633. The reversal of 551321604 is 406123155.

551321604 is a `hidden beast` number, since 5 + 51 + 3 + 2 + 1 + 604 = 666.

It can be written as a sum of positive squares in only one way, i.e., 549808704 + 1512900 = 23448^2 + 1230^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×551321604² = 607911022074265632, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7657209 + ... + 7657280.

It is an arithmetic number, because the mean of its divisors is an integer number (77423255).

Almost surely, 2^551321604 is an apocalyptic number.

It is an amenable number.

551321604 is an abundant number, since it is smaller than the sum of its proper divisors (842296986).

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

551321604 is a wasteful number, since it uses less digits than its factorization.

551321604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15314499 (or 15314494 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 551321604 is about 23480.2385848185. The cubic root of 551321604 is about 819.9769991565.

Adding to 551321604 its reverse (406123155), we get a palindrome (957444759).

The spelling of 551321604 in words is "five hundred fifty-one million, three hundred twenty-one thousand, six hundred four".