156991965 has 32 divisors (see below), whose sum is σ = 284753280. Its totient is φ = 73218816.

The previous prime is 156991949. The next prime is 156992009. The reversal of 156991965 is 569199651.

It is a happy number.

It is not a de Polignac number, because 156991965 - 2⁴ = 156991949 is a prime.

It is a super-2 number, since 2×156991965² = 49292954149122450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17482 + ... + 24891.

It is an arithmetic number, because the mean of its divisors is an integer number (8898540).

Almost surely, 2^156991965 is an apocalyptic number.

156991965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

156991965 is a deficient number, since it is larger than the sum of its proper divisors (127761315).

156991965 is a wasteful number, since it uses less digits than its factorization.

156991965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42413.

The product of its digits is 656100, while the sum is 51.

The square root of 156991965 is about 12529.6434506334. The cubic root of 156991965 is about 539.4598680094.

The spelling of 156991965 in words is "one hundred fifty-six million, nine hundred ninety-one thousand, nine hundred sixty-five".