156657993 has 16 divisors (see below), whose sum is σ = 213579840. Its totient is φ = 102110976.

The previous prime is 156657989. The next prime is 156658049. The reversal of 156657993 is 399756651.

It is not a de Polignac number, because 156657993 - 2² = 156657989 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (156657923) 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, 24693 + ... + 30381.

It is an arithmetic number, because the mean of its divisors is an integer number (13348740).

Almost surely, 2^156657993 is an apocalyptic number.

It is an amenable number.

156657993 is a deficient number, since it is larger than the sum of its proper divisors (56921847).

156657993 is a wasteful number, since it uses less digits than its factorization.

156657993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5896.

The product of its digits is 1530900, while the sum is 51.

The square root of 156657993 is about 12516.3090805557. The cubic root of 156657993 is about 539.0770620103.

The spelling of 156657993 in words is "one hundred fifty-six million, six hundred fifty-seven thousand, nine hundred ninety-three".