156311921 has 2 divisors, whose sum is σ = 156311922. Its totient is φ = 156311920.

The previous prime is 156311899. The next prime is 156311927. The reversal of 156311921 is 129113651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 141871921 + 14440000 = 11911^2 + 3800^2 .

It is a cyclic number.

It is not a de Polignac number, because 156311921 - 2¹⁴ = 156295537 is a prime.

It is not a weakly prime, because it can be changed into another prime (156311927) 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, 78155960 + 78155961.

It is an arithmetic number, because the mean of its divisors is an integer number (78155961).

Almost surely, 2^156311921 is an apocalyptic number.

It is an amenable number.

156311921 is a deficient number, since it is larger than the sum of its proper divisors (1).

156311921 is an equidigital number, since it uses as much as digits as its factorization.

156311921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 29.

The square root of 156311921 is about 12502.4765946592. The cubic root of 156311921 is about 538.6798123116.

The spelling of 156311921 in words is "one hundred fifty-six million, three hundred eleven thousand, nine hundred twenty-one".