156465721 has 2 divisors, whose sum is σ = 156465722. Its totient is φ = 156465720.

The previous prime is 156465719. The next prime is 156465737. The reversal of 156465721 is 127564651.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85821696 + 70644025 = 9264^2 + 8405^2 .

It is a cyclic number.

It is not a de Polignac number, because 156465721 - 2¹ = 156465719 is a prime.

Together with 156465719, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (156465761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78232860 + 78232861.

It is an arithmetic number, because the mean of its divisors is an integer number (78232861).

Almost surely, 2^156465721 is an apocalyptic number.

It is an amenable number.

156465721 is a deficient number, since it is larger than the sum of its proper divisors (1).

156465721 is an equidigital number, since it uses as much as digits as its factorization.

156465721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50400, while the sum is 37.

The square root of 156465721 is about 12508.6258637790. The cubic root of 156465721 is about 538.8564288207.

The spelling of 156465721 in words is "one hundred fifty-six million, four hundred sixty-five thousand, seven hundred twenty-one".