2156670857 has 8 divisors (see below), whose sum is σ = 2355579840. Its totient is φ = 1958236560.

The previous prime is 2156670853. The next prime is 2156670871. The reversal of 2156670857 is 7580766512.

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 2156670857 - 2² = 2156670853 is a prime.

It is a super-2 number, since 2×2156670857² = 9302458370866228898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2156670853) 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, 109133 + ... + 127370.

It is an arithmetic number, because the mean of its divisors is an integer number (294447480).

Almost surely, 2^2156670857 is an apocalyptic number.

It is an amenable number.

2156670857 is a deficient number, since it is larger than the sum of its proper divisors (198908983).

2156670857 is a wasteful number, since it uses less digits than its factorization.

2156670857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237343.

The product of its (nonzero) digits is 705600, while the sum is 47.

The square root of 2156670857 is about 46439.9704672602. The cubic root of 2156670857 is about 1291.9963594631.

The spelling of 2156670857 in words is "two billion, one hundred fifty-six million, six hundred seventy thousand, eight hundred fifty-seven".