156993857 has 8 divisors (see below), whose sum is σ = 157975272. Its totient is φ = 156016000.

The previous prime is 156993841. The next prime is 156993869. The reversal of 156993857 is 758399651.

It can be written as a sum of positive squares in 4 ways, for example, as 61716736 + 95277121 = 7856^2 + 9761^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 156993857 - 2⁴ = 156993841 is a prime.

It is a super-2 number, since 2×156993857² = 49294142271472898, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 156993799 and 156993808.

It is not an unprimeable number, because it can be changed into a prime (156993887) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196583 + ... + 197379.

It is an arithmetic number, because the mean of its divisors is an integer number (19746909).

Almost surely, 2^156993857 is an apocalyptic number.

It is an amenable number.

156993857 is a deficient number, since it is larger than the sum of its proper divisors (981415).

156993857 is an equidigital number, since it uses as much as digits as its factorization.

156993857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1779.

The product of its digits is 2041200, while the sum is 53.

The square root of 156993857 is about 12529.7189513572. The cubic root of 156993857 is about 539.4620351139.

The spelling of 156993857 in words is "one hundred fifty-six million, nine hundred ninety-three thousand, eight hundred fifty-seven".