31261216213 has 4 divisors (see below), whose sum is σ = 31261904608. Its totient is φ = 31260527820.

The previous prime is 31261216201. The next prime is 31261216229.

31261216213 is nontrivially palindromic in base 10.

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 31261216213 - 2⁹ = 31261215701 is a prime.

It is a super-2 number, since 2×31261216213² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31261210213) 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, 270873 + ... + 368638.

It is an arithmetic number, because the mean of its divisors is an integer number (7815476152).

Almost surely, 2^31261216213 is an apocalyptic number.

It is an amenable number.

31261216213 is a deficient number, since it is larger than the sum of its proper divisors (688395).

31261216213 is an equidigital number, since it uses as much as digits as its factorization.

31261216213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688394.

The product of its digits is 2592, while the sum is 28.

The spelling of 31261216213 in words is "thirty-one billion, two hundred sixty-one million, two hundred sixteen thousand, two hundred thirteen".