215723161 has 2 divisors, whose sum is σ = 215723162. Its totient is φ = 215723160.

The previous prime is 215723117. The next prime is 215723177. The reversal of 215723161 is 161327512.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108993600 + 106729561 = 10440^2 + 10331^2 .

It is a cyclic number.

It is not a de Polignac number, because 215723161 - 2⁷ = 215723033 is a prime.

It is not a weakly prime, because it can be changed into another prime (215723111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107861580 + 107861581.

It is an arithmetic number, because the mean of its divisors is an integer number (107861581).

Almost surely, 2^215723161 is an apocalyptic number.

It is an amenable number.

215723161 is a deficient number, since it is larger than the sum of its proper divisors (1).

215723161 is an equidigital number, since it uses as much as digits as its factorization.

215723161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2520, while the sum is 28.

The square root of 215723161 is about 14687.5171829687. The cubic root of 215723161 is about 599.7435580040.

The spelling of 215723161 in words is "two hundred fifteen million, seven hundred twenty-three thousand, one hundred sixty-one".