857528821 has 6 divisors (see below), whose sum is σ = 859796822. Its totient is φ = 855263880.

The previous prime is 857528813. The next prime is 857528827. The reversal of 857528821 is 128825758.

It can be written as a sum of positive squares in only one way, i.e., 699020721 + 158508100 = 26439^2 + 12590^2 .

It is not a de Polignac number, because 857528821 - 2³ = 857528813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857528827) 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, 680490 + ... + 681748.

Almost surely, 2^857528821 is an apocalyptic number.

It is an amenable number.

857528821 is a deficient number, since it is larger than the sum of its proper divisors (2268001).

857528821 is an frugal number, since it uses more digits than its factorization.

857528821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3059 (or 1800 counting only the distinct ones).

The product of its digits is 358400, while the sum is 46.

The square root of 857528821 is about 29283.5930343256. The cubic root of 857528821 is about 950.0568095298.

The spelling of 857528821 in words is "eight hundred fifty-seven million, five hundred twenty-eight thousand, eight hundred twenty-one".