156491985 has 16 divisors (see below), whose sum is σ = 269648064. Its totient is φ = 77042112.

The previous prime is 156491983. The next prime is 156492019. The reversal of 156491985 is 589194651.

It is not a de Polignac number, because 156491985 - 2¹ = 156491983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (156491983) 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, 401067 + ... + 401456.

It is an arithmetic number, because the mean of its divisors is an integer number (16853004).

Almost surely, 2^156491985 is an apocalyptic number.

156491985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

156491985 is a deficient number, since it is larger than the sum of its proper divisors (113156079).

156491985 is a wasteful number, since it uses less digits than its factorization.

156491985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802544.

The product of its digits is 388800, while the sum is 48.

The square root of 156491985 is about 12509.6756552678. The cubic root of 156491985 is about 538.8865775616.

The spelling of 156491985 in words is "one hundred fifty-six million, four hundred ninety-one thousand, nine hundred eighty-five".