20291313 has 32 divisors (see below), whose sum is σ = 33048576. Its totient is φ = 10821888.

The previous prime is 20291311. The next prime is 20291317. The reversal of 20291313 is 31319202.

It is a happy number.

It is not a de Polignac number, because 20291313 - 2¹ = 20291311 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 20291313.

It is not an unprimeable number, because it can be changed into a prime (20291311) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20281 + ... + 21257.

It is an arithmetic number, because the mean of its divisors is an integer number (1032768).

Almost surely, 2^20291313 is an apocalyptic number.

20291313 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

20291313 is a deficient number, since it is larger than the sum of its proper divisors (12757263).

20291313 is a wasteful number, since it uses less digits than its factorization.

20291313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1053.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 20291313 is about 4504.5879944785. The cubic root of 20291313 is about 272.7533227743.

The spelling of 20291313 in words is "twenty million, two hundred ninety-one thousand, three hundred thirteen".