221031020131 has 4 divisors (see below), whose sum is σ = 226422020664. Its totient is φ = 215640019600.

The previous prime is 221031020123. The next prime is 221031020173. The reversal of 221031020131 is 131020130122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221031020131 - 2³ = 221031020123 is a prime.

It is a super-2 number, since 2×221031020131² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221031020101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2695500205 + ... + 2695500286.

It is an arithmetic number, because the mean of its divisors is an integer number (56605505166).

Almost surely, 2^221031020131 is an apocalyptic number.

221031020131 is a deficient number, since it is larger than the sum of its proper divisors (5391000533).

221031020131 is an equidigital number, since it uses as much as digits as its factorization.

221031020131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5391000532.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 221031020131 its reverse (131020130122), we get a palindrome (352051150253).

The spelling of 221031020131 in words is "two hundred twenty-one billion, thirty-one million, twenty thousand, one hundred thirty-one".