166831478257 has 4 divisors (see below), whose sum is σ = 167163151680. Its totient is φ = 166499804836.

The previous prime is 166831478251. The next prime is 166831478279. The reversal of 166831478257 is 752874138661.

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 a cyclic number.

It is not a de Polignac number, because 166831478257 - 2¹⁵ = 166831445489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166831478251) 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, 165835957 + ... + 165836962.

It is an arithmetic number, because the mean of its divisors is an integer number (41790787920).

Almost surely, 2^166831478257 is an apocalyptic number.

It is an amenable number.

166831478257 is a deficient number, since it is larger than the sum of its proper divisors (331673423).

166831478257 is an equidigital number, since it uses as much as digits as its factorization.

166831478257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331673422.

The product of its digits is 13547520, while the sum is 58.

The spelling of 166831478257 in words is "one hundred sixty-six billion, eight hundred thirty-one million, four hundred seventy-eight thousand, two hundred fifty-seven".