55938801821 has 16 divisors (see below), whose sum is σ = 64831065600. Its totient is φ = 47273511168.

The previous prime is 55938801817. The next prime is 55938801827. The reversal of 55938801821 is 12810883955.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 55938801821 - 2² = 55938801817 is a prime.

It is a super-2 number, since 2×55938801821² (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 55938801821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55938801827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 320741 + ... + 463413.

It is an arithmetic number, because the mean of its divisors is an integer number (4051941600).

Almost surely, 2^55938801821 is an apocalyptic number.

It is an amenable number.

55938801821 is a deficient number, since it is larger than the sum of its proper divisors (8892263779).

55938801821 is a wasteful number, since it uses less digits than its factorization.

55938801821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143468.

The product of its (nonzero) digits is 691200, while the sum is 50.

The spelling of 55938801821 in words is "fifty-five billion, nine hundred thirty-eight million, eight hundred one thousand, eight hundred twenty-one".