156391989 has 16 divisors (see below), whose sum is σ = 229787712. Its totient is φ = 94002048.

The previous prime is 156391987. The next prime is 156392009. The reversal of 156391989 is 989193651.

It is a happy number.

It is not a de Polignac number, because 156391989 - 2¹ = 156391987 is a prime.

It is a super-2 number, since 2×156391989² = 48916908446752242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156391987) 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 in 15 ways as a sum of consecutive naturals, for example, 44952 + ... + 48305.

It is an arithmetic number, because the mean of its divisors is an integer number (14361732).

Almost surely, 2^156391989 is an apocalyptic number.

It is an amenable number.

156391989 is a deficient number, since it is larger than the sum of its proper divisors (73395723).

156391989 is a wasteful number, since it uses less digits than its factorization.

156391989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93316.

The product of its digits is 524880, while the sum is 51.

The square root of 156391989 is about 12505.6782702899. The cubic root of 156391989 is about 538.7717729944.

The spelling of 156391989 in words is "one hundred fifty-six million, three hundred ninety-one thousand, nine hundred eighty-nine".