55779397520 has 160 divisors (see below), whose sum is σ = 162503884800. Its totient is φ = 17298040320.

The previous prime is 55779397511. The next prime is 55779397537. The reversal of 55779397520 is 2579397755.

It is a happy number.

It is a super-2 number, since 2×55779397520² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 55779397520.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1203089 + ... + 1248591.

It is an arithmetic number, because the mean of its divisors is an integer number (1015649280).

Almost surely, 2^55779397520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55779397520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81251942400).

55779397520 is an abundant number, since it is smaller than the sum of its proper divisors (106724487280).

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

55779397520 is a wasteful number, since it uses less digits than its factorization.

55779397520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45733 (or 45727 counting only the distinct ones).

The product of its (nonzero) digits is 20837250, while the sum is 59.

The spelling of 55779397520 in words is "fifty-five billion, seven hundred seventy-nine million, three hundred ninety-seven thousand, five hundred twenty".