31120231021 has 4 divisors (see below), whose sum is σ = 33949342944. Its totient is φ = 28291119100.

The previous prime is 31120231019. The next prime is 31120231031. The reversal of 31120231021 is 12013202113.

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 a cyclic number.

It is not a de Polignac number, because 31120231021 - 2¹ = 31120231019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31120230986 and 31120231004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31120231031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1414555945 + ... + 1414555966.

It is an arithmetic number, because the mean of its divisors is an integer number (8487335736).

Almost surely, 2^31120231021 is an apocalyptic number.

It is an amenable number.

31120231021 is a deficient number, since it is larger than the sum of its proper divisors (2829111923).

31120231021 is a wasteful number, since it uses less digits than its factorization.

31120231021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2829111922.

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

Adding to 31120231021 its reverse (12013202113), we get a palindrome (43133433134).

The spelling of 31120231021 in words is "thirty-one billion, one hundred twenty million, two hundred thirty-one thousand, twenty-one".