157865781 has 4 divisors (see below), whose sum is σ = 210487712. Its totient is φ = 105243852.

The previous prime is 157865759. The next prime is 157865783. The reversal of 157865781 is 187568751.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 157865781 - 2⁵ = 157865749 is a prime.

It is a super-2 number, since 2×157865781² = 49843209621479922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 157865781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157865783) 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, 26310961 + ... + 26310966.

It is an arithmetic number, because the mean of its divisors is an integer number (52621928).

Almost surely, 2^157865781 is an apocalyptic number.

It is an amenable number.

157865781 is a deficient number, since it is larger than the sum of its proper divisors (52621931).

157865781 is an equidigital number, since it uses as much as digits as its factorization.

157865781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52621930.

The product of its digits is 470400, while the sum is 48.

The square root of 157865781 is about 12564.4650104969. The cubic root of 157865781 is about 540.4588931858.

The spelling of 157865781 in words is "one hundred fifty-seven million, eight hundred sixty-five thousand, seven hundred eighty-one".