31544123221 has 32 divisors (see below), whose sum is σ = 35157032960. Its totient is φ = 28123490304.

The previous prime is 31544123213. The next prime is 31544123243. The reversal of 31544123221 is 12232144513.

It is not a de Polignac number, because 31544123221 - 2³ = 31544123213 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31544123221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31544123201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9519661 + ... + 9522973.

It is an arithmetic number, because the mean of its divisors is an integer number (1098657280).

Almost surely, 2^31544123221 is an apocalyptic number.

It is an amenable number.

31544123221 is a deficient number, since it is larger than the sum of its proper divisors (3612909739).

31544123221 is a wasteful number, since it uses less digits than its factorization.

31544123221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3605.

The product of its digits is 5760, while the sum is 28.

Adding to 31544123221 its reverse (12232144513), we get a palindrome (43776267734).

The spelling of 31544123221 in words is "thirty-one billion, five hundred forty-four million, one hundred twenty-three thousand, two hundred twenty-one".