31311132231021 has 16 divisors (see below), whose sum is σ = 41815024787328. Its totient is φ = 20840665003200.

The previous prime is 31311132230971. The next prime is 31311132231037. The reversal of 31311132231021 is 12013223111313.

It is not a de Polignac number, because 31311132231021 - 2²¹ = 31311130133869 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31311132230982 and 31311132231000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31311132231061) 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, 174484675 + ... + 174664031.

It is an arithmetic number, because the mean of its divisors is an integer number (2613439049208).

Almost surely, 2^{31311132231021} is an apocalyptic number.

It is an amenable number.

31311132231021 is a deficient number, since it is larger than the sum of its proper divisors (10503892556307).

31311132231021 is a wasteful number, since it uses less digits than its factorization.

31311132231021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272212.

The product of its (nonzero) digits is 648, while the sum is 24.

Adding to 31311132231021 its reverse (12013223111313), we get a palindrome (43324355342334).

The spelling of 31311132231021 in words is "thirty-one trillion, three hundred eleven billion, one hundred thirty-two million, two hundred thirty-one thousand, twenty-one".