20155913 has 2 divisors, whose sum is σ = 20155914. Its totient is φ = 20155912.

The previous prime is 20155909. The next prime is 20155951. The reversal of 20155913 is 31955102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10220809 + 9935104 = 3197^2 + 3152^2 .

It is a cyclic number.

It is not a de Polignac number, because 20155913 - 2² = 20155909 is a prime.

It is not a weakly prime, because it can be changed into another prime (20155813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10077956 + 10077957.

It is an arithmetic number, because the mean of its divisors is an integer number (10077957).

Almost surely, 2^20155913 is an apocalyptic number.

It is an amenable number.

20155913 is a deficient number, since it is larger than the sum of its proper divisors (1).

20155913 is an equidigital number, since it uses as much as digits as its factorization.

20155913 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 20155913 is about 4489.5337174366. The cubic root of 20155913 is about 272.1452916462.

The spelling of 20155913 in words is "twenty million, one hundred fifty-five thousand, nine hundred thirteen".