821437652 has 24 divisors (see below), whose sum is σ = 1644026496. Its totient is φ = 351798048.

The previous prime is 821437649. The next prime is 821437679. The reversal of 821437652 is 256734128.

It is a happy number.

It is a super-2 number, since 2×821437652² = 1349519632246546208, which contains 22 as substring.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33698 + ... + 52710.

It is an arithmetic number, because the mean of its divisors is an integer number (68501104).

Almost surely, 2^821437652 is an apocalyptic number.

It is an amenable number.

821437652 is an abundant number, since it is smaller than the sum of its proper divisors (822588844).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

821437652 is a wasteful number, since it uses less digits than its factorization.

821437652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20567 (or 20565 counting only the distinct ones).

The product of its digits is 80640, while the sum is 38.

The square root of 821437652 is about 28660.7336263397. The cubic root of 821437652 is about 936.5368462546.

The spelling of 821437652 in words is "eight hundred twenty-one million, four hundred thirty-seven thousand, six hundred fifty-two".