31020013 has 4 divisors (see below), whose sum is σ = 31102240. Its totient is φ = 30937788.

The previous prime is 31020007. The next prime is 31020079. The reversal of 31020013 is 31002013.

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, and also an emirpimes, since its reverse is a distinct semiprime: 31002013 = 7 ⋅4428859.

It is a cyclic number.

It is not a de Polignac number, because 31020013 - 2¹⁷ = 30888941 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 (31020713) 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, 40545 + ... + 41302.

It is an arithmetic number, because the mean of its divisors is an integer number (7775560).

Almost surely, 2^31020013 is an apocalyptic number.

It is an amenable number.

31020013 is a deficient number, since it is larger than the sum of its proper divisors (82227).

31020013 is an equidigital number, since it uses as much as digits as its factorization.

31020013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82226.

The product of its (nonzero) digits is 18, while the sum is 10.

The square root of 31020013 is about 5569.5612933157. The cubic root of 31020013 is about 314.2056511821.

Adding to 31020013 its reverse (31002013), we get a palindrome (62022026).

The spelling of 31020013 in words is "thirty-one million, twenty thousand, thirteen".