55128189531 has 16 divisors (see below), whose sum is σ = 73663992864. Its totient is φ = 36672344064.

The previous prime is 55128189527. The next prime is 55128189581. The reversal of 55128189531 is 13598182155.

It is not a de Polignac number, because 55128189531 - 2² = 55128189527 is a prime.

It is a super-2 number, since 2×55128189531² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55128189511) 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, 2746825 + ... + 2766821.

It is an arithmetic number, because the mean of its divisors is an integer number (4603999554).

Almost surely, 2^55128189531 is an apocalyptic number.

55128189531 is a deficient number, since it is larger than the sum of its proper divisors (18535803333).

55128189531 is a wasteful number, since it uses less digits than its factorization.

55128189531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21950.

The product of its digits is 432000, while the sum is 48.

The spelling of 55128189531 in words is "fifty-five billion, one hundred twenty-eight million, one hundred eighty-nine thousand, five hundred thirty-one".