551115561 has 16 divisors (see below), whose sum is σ = 761038848. Its totient is φ = 354522000.

The previous prime is 551115533. The next prime is 551115647. The reversal of 551115561 is 165511155.

It is not a de Polignac number, because 551115561 - 2⁵ = 551115529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (551115661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17515 + ... + 37536.

It is an arithmetic number, because the mean of its divisors is an integer number (47564928).

Almost surely, 2^551115561 is an apocalyptic number.

It is an amenable number.

551115561 is a deficient number, since it is larger than the sum of its proper divisors (209923287).

551115561 is a wasteful number, since it uses less digits than its factorization.

551115561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55172.

The product of its digits is 3750, while the sum is 30.

The square root of 551115561 is about 23475.8505916186. The cubic root of 551115561 is about 819.8748376287.

The spelling of 551115561 in words is "five hundred fifty-one million, one hundred fifteen thousand, five hundred sixty-one".