55779625566 has 64 divisors (see below), whose sum is σ = 141815923200. Its totient is φ = 15919780608.

The previous prime is 55779625537. The next prime is 55779625637. The reversal of 55779625566 is 66552697755.

It is a happy number.

55779625566 is a `hidden beast` number, since 5 + 5 + 7 + 7 + 9 + 62 + 5 + 566 = 666.

It is a super-2 number, since 2×55779625566² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 271741 + ... + 430583.

It is an arithmetic number, because the mean of its divisors is an integer number (2215873800).

Almost surely, 2^55779625566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55779625566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70907961600).

55779625566 is an abundant number, since it is smaller than the sum of its proper divisors (86036297634).

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

55779625566 is a wasteful number, since it uses less digits than its factorization.

55779625566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159790 (or 159784 counting only the distinct ones).

The product of its digits is 119070000, while the sum is 63.

The spelling of 55779625566 in words is "fifty-five billion, seven hundred seventy-nine million, six hundred twenty-five thousand, five hundred sixty-six".