31311155340021 has 4 divisors (see below), whose sum is σ = 41748207120032. Its totient is φ = 20874103560012.

The previous prime is 31311155340013. The next prime is 31311155340053. The reversal of 31311155340021 is 12004355111313.

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 not a de Polignac number, because 31311155340021 - 2³ = 31311155340013 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 (31311155340011) 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, 5218525890001 + ... + 5218525890006.

It is an arithmetic number, because the mean of its divisors is an integer number (10437051780008).

Almost surely, 2^{31311155340021} is an apocalyptic number.

It is an amenable number.

31311155340021 is a deficient number, since it is larger than the sum of its proper divisors (10437051780011).

31311155340021 is a wasteful number, since it uses less digits than its factorization.

31311155340021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10437051780010.

The product of its (nonzero) digits is 5400, while the sum is 30.

The spelling of 31311155340021 in words is "thirty-one trillion, three hundred eleven billion, one hundred fifty-five million, three hundred forty thousand, twenty-one".