31213005 has 16 divisors (see below), whose sum is σ = 50011584. Its totient is φ = 16623360.

The previous prime is 31212899. The next prime is 31213009. The reversal of 31213005 is 50031213.

It is a happy number.

It is not a de Polignac number, because 31213005 - 2¹⁴ = 31196621 is a prime.

It is a super-2 number, since 2×31213005² = 1948503362260050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31213009) 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, 16677 + ... + 18453.

It is an arithmetic number, because the mean of its divisors is an integer number (3125724).

Almost surely, 2^31213005 is an apocalyptic number.

It is an amenable number.

31213005 is a deficient number, since it is larger than the sum of its proper divisors (18798579).

31213005 is a wasteful number, since it uses less digits than its factorization.

31213005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2956.

The product of its (nonzero) digits is 90, while the sum is 15.

The square root of 31213005 is about 5586.8600304643. The cubic root of 31213005 is about 314.8559179815.

Adding to 31213005 its reverse (50031213), we get a palindrome (81244218).

The spelling of 31213005 in words is "thirty-one million, two hundred thirteen thousand, five".