55536621820 has 12 divisors (see below), whose sum is σ = 116626905864. Its totient is φ = 22214648720.

The previous prime is 55536621779. The next prime is 55536621841. The reversal of 55536621820 is 2812663555.

It is a super-2 number, since 2×55536621820² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1388415526 + ... + 1388415565.

It is an arithmetic number, because the mean of its divisors is an integer number (9718908822).

Almost surely, 2^55536621820 is an apocalyptic number.

It is an amenable number.

55536621820 is an abundant number, since it is smaller than the sum of its proper divisors (61090284044).

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

55536621820 is a wasteful number, since it uses less digits than its factorization.

55536621820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2776831100 (or 2776831098 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 43.

The spelling of 55536621820 in words is "fifty-five billion, five hundred thirty-six million, six hundred twenty-one thousand, eight hundred twenty".