156409381 has 2 divisors, whose sum is σ = 156409382. Its totient is φ = 156409380.

The previous prime is 156409369. The next prime is 156409391. The reversal of 156409381 is 183904651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108868356 + 47541025 = 10434^2 + 6895^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-156409381 is a prime.

It is a super-2 number, since 2×156409381² = 48927788929606322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 156409381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (156409391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78204690 + 78204691.

It is an arithmetic number, because the mean of its divisors is an integer number (78204691).

Almost surely, 2^156409381 is an apocalyptic number.

It is an amenable number.

156409381 is a deficient number, since it is larger than the sum of its proper divisors (1).

156409381 is an equidigital number, since it uses as much as digits as its factorization.

156409381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 156409381 is about 12506.3736150812. The cubic root of 156409381 is about 538.7917441182.

The spelling of 156409381 in words is "one hundred fifty-six million, four hundred nine thousand, three hundred eighty-one".