31220013 has 16 divisors (see below), whose sum is σ = 45591552. Its totient is φ = 18846000.

The previous prime is 31220011. The next prime is 31220023. The reversal of 31220013 is 31002213.

It is a happy number.

It is not a de Polignac number, because 31220013 - 2¹ = 31220011 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31220011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7198 + ... + 10688.

It is an arithmetic number, because the mean of its divisors is an integer number (2849472).

Almost surely, 2^31220013 is an apocalyptic number.

31220013 is a gapful number since it is divisible by the number (33) formed by its first and last digit.

It is an amenable number.

31220013 is a deficient number, since it is larger than the sum of its proper divisors (14371539).

31220013 is a wasteful number, since it uses less digits than its factorization.

31220013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3776.

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 31220013 is about 5587.4871811933. The cubic root of 31220013 is about 314.8794802238.

Adding to 31220013 its reverse (31002213), we get a palindrome (62222226).

It can be divided in two parts, 312200 and 13, that added together give a palindrome (312213).

The spelling of 31220013 in words is "thirty-one million, two hundred twenty thousand, thirteen".