857505631 has 2 divisors, whose sum is σ = 857505632. Its totient is φ = 857505630.

The previous prime is 857505617. The next prime is 857505637. The reversal of 857505631 is 136505758.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 857505631 - 2⁷ = 857505503 is a prime.

It is a super-2 number, since 2×857505631² = 1470631814393416322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (857505637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428752815 + 428752816.

It is an arithmetic number, because the mean of its divisors is an integer number (428752816).

Almost surely, 2^857505631 is an apocalyptic number.

857505631 is a deficient number, since it is larger than the sum of its proper divisors (1).

857505631 is an equidigital number, since it uses as much as digits as its factorization.

857505631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126000, while the sum is 40.

The square root of 857505631 is about 29283.1970761391. The cubic root of 857505631 is about 950.0482453799.

The spelling of 857505631 in words is "eight hundred fifty-seven million, five hundred five thousand, six hundred thirty-one".