157831581 has 8 divisors (see below), whose sum is σ = 211956640. Its totient is φ = 104463792.

The previous prime is 157831577. The next prime is 157831631. The reversal of 157831581 is 185138751.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 157831581 - 2² = 157831577 is a prime.

It is a super-2 number, since 2×157831581² = 49821615921919122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157831501) 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 7 ways as a sum of consecutive naturals, for example, 188830 + ... + 189663.

It is an arithmetic number, because the mean of its divisors is an integer number (26494580).

Almost surely, 2^157831581 is an apocalyptic number.

It is an amenable number.

157831581 is a deficient number, since it is larger than the sum of its proper divisors (54125059).

157831581 is a wasteful number, since it uses less digits than its factorization.

157831581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378635.

The product of its digits is 33600, while the sum is 39.

The square root of 157831581 is about 12563.1039556313. The cubic root of 157831581 is about 540.4198620778.

The spelling of 157831581 in words is "one hundred fifty-seven million, eight hundred thirty-one thousand, five hundred eighty-one".