55155551561 has 8 divisors (see below), whose sum is σ = 60198520800. Its totient is φ = 50117387040.

The previous prime is 55155551551. The next prime is 55155551593. The reversal of 55155551561 is 16515555155.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 55155551561 - 2¹⁰ = 55155550537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55155551551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1177151 + ... + 1223108.

It is an arithmetic number, because the mean of its divisors is an integer number (7524815100).

Almost surely, 2^55155551561 is an apocalyptic number.

It is an amenable number.

55155551561 is a deficient number, since it is larger than the sum of its proper divisors (5042969239).

55155551561 is a wasteful number, since it uses less digits than its factorization.

55155551561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2402359.

The product of its digits is 468750, while the sum is 44.

The spelling of 55155551561 in words is "fifty-five billion, one hundred fifty-five million, five hundred fifty-one thousand, five hundred sixty-one".