551601561 has 16 divisors (see below), whose sum is σ = 854784000. Its totient is φ = 309857808.

The previous prime is 551601529. The next prime is 551601563. The reversal of 551601561 is 165106155.

It is not a de Polignac number, because 551601561 - 2⁵ = 551601529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (551601563) 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, 221361 + ... + 223838.

It is an arithmetic number, because the mean of its divisors is an integer number (53424000).

Almost surely, 2^551601561 is an apocalyptic number.

It is an amenable number.

551601561 is a deficient number, since it is larger than the sum of its proper divisors (303182439).

551601561 is a wasteful number, since it uses less digits than its factorization.

551601561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445268.

The product of its (nonzero) digits is 4500, while the sum is 30.

The square root of 551601561 is about 23486.1993732490. The cubic root of 551601561 is about 820.1157684061.

The spelling of 551601561 in words is "five hundred fifty-one million, six hundred one thousand, five hundred sixty-one".