821921292 has 36 divisors (see below), whose sum is σ = 2078625640. Its totient is φ = 273843072.

The previous prime is 821921291. The next prime is 821921299. The reversal of 821921292 is 292129128.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×821921292² = 1351109220485898528, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (821921291) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 97959 + ... + 106017.

Almost surely, 2^821921292 is an apocalyptic number.

It is an amenable number.

821921292 is an abundant number, since it is smaller than the sum of its proper divisors (1256704348).

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

821921292 is a wasteful number, since it uses less digits than its factorization.

821921292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10902 (or 10897 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 821921292 is about 28669.1697124280. The cubic root of 821921292 is about 936.7206126119.

The spelling of 821921292 in words is "eight hundred twenty-one million, nine hundred twenty-one thousand, two hundred ninety-two".