821426913 has 20 divisors (see below), whose sum is σ = 1250228628. Its totient is φ = 537282720.

The previous prime is 821426897. The next prime is 821426959. The reversal of 821426913 is 319624128.

It can be written as a sum of positive squares in 2 ways, for example, as 706336929 + 115089984 = 26577^2 + 10728^2 .

It is not a de Polignac number, because 821426913 - 2⁴ = 821426897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (821426413) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 91378 + ... + 99963.

Almost surely, 2^821426913 is an apocalyptic number.

It is an amenable number.

821426913 is a deficient number, since it is larger than the sum of its proper divisors (428801715).

821426913 is a wasteful number, since it uses less digits than its factorization.

821426913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191406 (or 191397 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 821426913 is about 28660.5462788133. The cubic root of 821426913 is about 936.5327649901.

The spelling of 821426913 in words is "eight hundred twenty-one million, four hundred twenty-six thousand, nine hundred thirteen".