31431122331021 has 48 divisors (see below), whose sum is σ = 53275140592128. Its totient is φ = 17481920659200.

The previous prime is 31431122331017. The next prime is 31431122331023. The reversal of 31431122331021 is 12013322113413.

31431122331021 is a `hidden beast` number, since 3 + 1 + 431 + 1 + 223 + 3 + 1 + 0 + 2 + 1 = 666.

It is not a de Polignac number, because 31431122331021 - 2² = 31431122331017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31431122331023) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13003266 + ... + 15229811.

It is an arithmetic number, because the mean of its divisors is an integer number (1109898762336).

Almost surely, 2^{31431122331021} is an apocalyptic number.

It is an amenable number.

31431122331021 is a deficient number, since it is larger than the sum of its proper divisors (21844018261107).

31431122331021 is a wasteful number, since it uses less digits than its factorization.

31431122331021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28233562 (or 28233559 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

Adding to 31431122331021 its reverse (12013322113413), we get a palindrome (43444444444434).

The spelling of 31431122331021 in words is "thirty-one trillion, four hundred thirty-one billion, one hundred twenty-two million, three hundred thirty-one thousand, twenty-one".