157831993 has 16 divisors (see below), whose sum is σ = 183061440. Its totient is φ = 134568000.

The previous prime is 157831991. The next prime is 157832011. The reversal of 157831993 is 399138751.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 157831993 - 2¹ = 157831991 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (157831991) 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, 17371 + ... + 24847.

It is an arithmetic number, because the mean of its divisors is an integer number (11441340).

Almost surely, 2^157831993 is an apocalyptic number.

It is an amenable number.

157831993 is a deficient number, since it is larger than the sum of its proper divisors (25229447).

157831993 is a wasteful number, since it uses less digits than its factorization.

157831993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7608.

The product of its digits is 204120, while the sum is 46.

The square root of 157831993 is about 12563.1203528423. The cubic root of 157831993 is about 540.4203323106.

The spelling of 157831993 in words is "one hundred fifty-seven million, eight hundred thirty-one thousand, nine hundred ninety-three".