157805781 has 16 divisors (see below), whose sum is σ = 254611584. Its totient is φ = 84870144.

The previous prime is 157805759. The next prime is 157805789. The reversal of 157805781 is 187508751.

It is not a de Polignac number, because 157805781 - 2⁵ = 157805749 is a prime.

It is a super-2 number, since 2×157805781² = 49805329034039922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157805789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 220660 + ... + 221373.

It is an arithmetic number, because the mean of its divisors is an integer number (15913224).

Almost surely, 2^157805781 is an apocalyptic number.

It is an amenable number.

157805781 is a deficient number, since it is larger than the sum of its proper divisors (96805803).

157805781 is a wasteful number, since it uses less digits than its factorization.

157805781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442060.

The product of its (nonzero) digits is 78400, while the sum is 42.

The square root of 157805781 is about 12562.0770973593. The cubic root of 157805781 is about 540.3904138264.

The spelling of 157805781 in words is "one hundred fifty-seven million, eight hundred five thousand, seven hundred eighty-one".