856993253 has 4 divisors (see below), whose sum is σ = 875227200. Its totient is φ = 838759308.

The previous prime is 856993229. The next prime is 856993259. The reversal of 856993253 is 352399658.

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 856993253 - 2²² = 852798949 is a prime.

It is a super-3 number, since 3×856993253³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856993259) 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, 9116903 + ... + 9116996.

It is an arithmetic number, because the mean of its divisors is an integer number (218806800).

Almost surely, 2^856993253 is an apocalyptic number.

It is an amenable number.

856993253 is a deficient number, since it is larger than the sum of its proper divisors (18233947).

856993253 is a wasteful number, since it uses less digits than its factorization.

856993253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18233946.

The product of its digits is 1749600, while the sum is 50.

The square root of 856993253 is about 29274.4470998173. The cubic root of 856993253 is about 949.8589829467.

The spelling of 856993253 in words is "eight hundred fifty-six million, nine hundred ninety-three thousand, two hundred fifty-three".