55372100021 has 4 divisors (see below), whose sum is σ = 63282400032. Its totient is φ = 47461800012.

The previous prime is 55372099921. The next prime is 55372100023. The reversal of 55372100021 is 12000127355.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 55372100021 - 2¹⁰ = 55372098997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55372100023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3955149995 + ... + 3955150008.

It is an arithmetic number, because the mean of its divisors is an integer number (15820600008).

Almost surely, 2^55372100021 is an apocalyptic number.

It is an amenable number.

55372100021 is a deficient number, since it is larger than the sum of its proper divisors (7910300011).

55372100021 is an equidigital number, since it uses as much as digits as its factorization.

55372100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7910300010.

The product of its (nonzero) digits is 2100, while the sum is 26.

Adding to 55372100021 its reverse (12000127355), we get a palindrome (67372227376).

The spelling of 55372100021 in words is "fifty-five billion, three hundred seventy-two million, one hundred thousand, twenty-one".