157197431 has 4 divisors (see below), whose sum is σ = 165471000. Its totient is φ = 148923864.

The previous prime is 157197401. The next prime is 157197437. The reversal of 157197431 is 134791751.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157197431 is a prime.

It is a super-2 number, since 2×157197431² = 49422064625999522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157197437) 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, 4136756 + ... + 4136793.

It is an arithmetic number, because the mean of its divisors is an integer number (41367750).

Almost surely, 2^157197431 is an apocalyptic number.

157197431 is a deficient number, since it is larger than the sum of its proper divisors (8273569).

157197431 is an equidigital number, since it uses as much as digits as its factorization.

157197431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8273568.

The product of its digits is 26460, while the sum is 38.

The square root of 157197431 is about 12537.8399654805. The cubic root of 157197431 is about 539.6951079498.

The spelling of 157197431 in words is "one hundred fifty-seven million, one hundred ninety-seven thousand, four hundred thirty-one".