551656565 has 4 divisors (see below), whose sum is σ = 661987884. Its totient is φ = 441325248.

The previous prime is 551656561. The next prime is 551656571. The reversal of 551656565 is 565656155.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 229310449 + 322346116 = 15143^2 + 17954^2 .

It is a cyclic number.

It is not a de Polignac number, because 551656565 - 2² = 551656561 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (551656561) 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, 55165652 + ... + 55165661.

It is an arithmetic number, because the mean of its divisors is an integer number (165496971).

Almost surely, 2^551656565 is an apocalyptic number.

It is an amenable number.

551656565 is a deficient number, since it is larger than the sum of its proper divisors (110331319).

551656565 is a wasteful number, since it uses less digits than its factorization.

551656565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110331318.

The product of its digits is 675000, while the sum is 44.

The square root of 551656565 is about 23487.3703296048. The cubic root of 551656565 is about 820.1430273019.

The spelling of 551656565 in words is "five hundred fifty-one million, six hundred fifty-six thousand, five hundred sixty-five".