851573821 has 12 divisors (see below), whose sum is σ = 982853472. Its totient is φ = 722770776.

The previous prime is 851573773. The next prime is 851573837. The reversal of 851573821 is 128375158.

It is not a de Polignac number, because 851573821 - 2²¹ = 849476669 is a prime.

It is a super-2 number, since 2×851573821² = 1450355945225080082, which contains 22 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 (851573851) 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 11 ways as a sum of consecutive naturals, for example, 68530 + ... + 79996.

It is an arithmetic number, because the mean of its divisors is an integer number (81904456).

Almost surely, 2^851573821 is an apocalyptic number.

It is an amenable number.

851573821 is a deficient number, since it is larger than the sum of its proper divisors (131279651).

851573821 is a wasteful number, since it uses less digits than its factorization.

851573821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11680 (or 11577 counting only the distinct ones).

The product of its digits is 67200, while the sum is 40.

The square root of 851573821 is about 29181.7377995211. The cubic root of 851573821 is about 947.8525161944.

The spelling of 851573821 in words is "eight hundred fifty-one million, five hundred seventy-three thousand, eight hundred twenty-one".