2157858 has 12 divisors (see below), whose sum is σ = 4675398. Its totient is φ = 719280.

The previous prime is 2157851. The next prime is 2157863. The reversal of 2157858 is 8587512.

It can be written as a sum of positive squares in only one way, i.e., 1447209 + 710649 = 1203^2 + 843^2 .

It is a super-2 number, since 2×2157858² = 9312702296328, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (2157851) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 59923 + ... + 59958.

2^2157858 is an apocalyptic number.

2157858 is an abundant number, since it is smaller than the sum of its proper divisors (2517540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2157858 is a wasteful number, since it uses less digits than its factorization.

2157858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119889 (or 119886 counting only the distinct ones).

The product of its digits is 22400, while the sum is 36.

The square root of 2157858 is about 1468.9649417192. The cubic root of 2157858 is about 129.2233376483.

The spelling of 2157858 in words is "two million, one hundred fifty-seven thousand, eight hundred fifty-eight".