156919997 has 32 divisors (see below), whose sum is σ = 181880160. Its totient is φ = 134369280.

The previous prime is 156919969. The next prime is 156920003. The reversal of 156919997 is 799919651.

It can be written as a sum of positive squares in 16 ways, for example, as 37039396 + 119880601 = 6086^2 + 10949^2 .

It is a cyclic number.

It is not a de Polignac number, because 156919997 - 2²² = 152725693 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156919927) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1439579 + ... + 1439687.

It is an arithmetic number, because the mean of its divisors is an integer number (5683755).

Almost surely, 2^156919997 is an apocalyptic number.

It is an amenable number.

156919997 is a deficient number, since it is larger than the sum of its proper divisors (24960163).

156919997 is a wasteful number, since it uses less digits than its factorization.

156919997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273.

The product of its digits is 1377810, while the sum is 56.

The square root of 156919997 is about 12526.7712120881. The cubic root of 156919997 is about 539.3774226396.

The spelling of 156919997 in words is "one hundred fifty-six million, nine hundred nineteen thousand, nine hundred ninety-seven".