157749331 has 4 divisors (see below), whose sum is σ = 158087592. Its totient is φ = 157411072.

The previous prime is 157749329. The next prime is 157749349. The reversal of 157749331 is 133947751.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 133947751 = 7 ⋅19135393.

It is a cyclic number.

It is not a de Polignac number, because 157749331 - 2¹ = 157749329 is a prime.

It is a super-2 number, since 2×157749331² = 49769702861895122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (157749311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168430 + ... + 169363.

It is an arithmetic number, because the mean of its divisors is an integer number (39521898).

Almost surely, 2^157749331 is an apocalyptic number.

157749331 is a deficient number, since it is larger than the sum of its proper divisors (338261).

157749331 is an equidigital number, since it uses as much as digits as its factorization.

157749331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338260.

The product of its digits is 79380, while the sum is 40.

The square root of 157749331 is about 12559.8300545827. The cubic root of 157749331 is about 540.3259703128.

The spelling of 157749331 in words is "one hundred fifty-seven million, seven hundred forty-nine thousand, three hundred thirty-one".