857406521 has 16 divisors (see below), whose sum is σ = 910166400. Its totient is φ = 805448448.

The previous prime is 857406497. The next prime is 857406527. The reversal of 857406521 is 125604758.

It is a cyclic number.

It is not a de Polignac number, because 857406521 - 2¹⁴ = 857390137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (857406527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2298491 + ... + 2298863.

It is an arithmetic number, because the mean of its divisors is an integer number (56885400).

Almost surely, 2^857406521 is an apocalyptic number.

It is an amenable number.

857406521 is a deficient number, since it is larger than the sum of its proper divisors (52759879).

857406521 is a wasteful number, since it uses less digits than its factorization.

857406521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1088.

The product of its (nonzero) digits is 67200, while the sum is 38.

The square root of 857406521 is about 29281.5047598309. The cubic root of 857406521 is about 950.0116419626.

The spelling of 857406521 in words is "eight hundred fifty-seven million, four hundred six thousand, five hundred twenty-one".