55581621057 has 12 divisors (see below), whose sum is σ = 85007185380. Its totient is φ = 34874742528.

The previous prime is 55581621041. The next prime is 55581621103. The reversal of 55581621057 is 75012618555.

55581621057 is a `hidden beast` number, since 5 + 5 + 581 + 6 + 2 + 10 + 57 = 666.

55581621057 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 38403848961 + 17177772096 = 195969^2 + 131064^2 .

It is not a de Polignac number, because 55581621057 - 2⁴ = 55581621041 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55581621757) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 181639132 + ... + 181639437.

It is an arithmetic number, because the mean of its divisors is an integer number (7083932115).

Almost surely, 2^55581621057 is an apocalyptic number.

It is an amenable number.

55581621057 is a deficient number, since it is larger than the sum of its proper divisors (29425564323).

55581621057 is a wasteful number, since it uses less digits than its factorization.

55581621057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363278592 (or 363278589 counting only the distinct ones).

The product of its (nonzero) digits is 420000, while the sum is 45.

The spelling of 55581621057 in words is "fifty-five billion, five hundred eighty-one million, six hundred twenty-one thousand, fifty-seven".