215431913 has 2 divisors, whose sum is σ = 215431914. Its totient is φ = 215431912.

The previous prime is 215431907. The next prime is 215431919. The reversal of 215431913 is 319134512.

It is a balanced prime because it is at equal distance from previous prime (215431907) and next prime (215431919).

It can be written as a sum of positive squares in only one way, i.e., 185313769 + 30118144 = 13613^2 + 5488^2 .

It is a cyclic number.

It is not a de Polignac number, because 215431913 - 2⁴ = 215431897 is a prime.

It is not a weakly prime, because it can be changed into another prime (215431919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107715956 + 107715957.

It is an arithmetic number, because the mean of its divisors is an integer number (107715957).

Almost surely, 2^215431913 is an apocalyptic number.

It is an amenable number.

215431913 is a deficient number, since it is larger than the sum of its proper divisors (1).

215431913 is an equidigital number, since it uses as much as digits as its factorization.

215431913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3240, while the sum is 29.

The square root of 215431913 is about 14677.5990202758. The cubic root of 215431913 is about 599.4735317055.

The spelling of 215431913 in words is "two hundred fifteen million, four hundred thirty-one thousand, nine hundred thirteen".