821570812 has 12 divisors (see below), whose sum is σ = 1487326680. Its totient is φ = 396620336.

The previous prime is 821570809. The next prime is 821570819. The reversal of 821570812 is 218075128.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821570819) 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, 3541138 + ... + 3541369.

It is an arithmetic number, because the mean of its divisors is an integer number (123943890).

Almost surely, 2^821570812 is an apocalyptic number.

It is an amenable number.

821570812 is a deficient number, since it is larger than the sum of its proper divisors (665755868).

821570812 is a wasteful number, since it uses less digits than its factorization.

821570812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7082540 (or 7082538 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 34.

The square root of 821570812 is about 28663.0565711335. The cubic root of 821570812 is about 936.5874496116.

The spelling of 821570812 in words is "eight hundred twenty-one million, five hundred seventy thousand, eight hundred twelve".