823270021 has 6 divisors (see below), whose sum is σ = 957681510. Its totient is φ = 705659976.

The previous prime is 823269919. The next prime is 823270043. The reversal of 823270021 is 120072328.

It can be written as a sum of positive squares in only one way, i.e., 494573121 + 328696900 = 22239^2 + 18130^2 .

It is not a de Polignac number, because 823270021 - 2²⁷ = 689052293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (823270321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8400666 + ... + 8400763.

It is an arithmetic number, because the mean of its divisors is an integer number (159613585).

Almost surely, 2^823270021 is an apocalyptic number.

It is an amenable number.

823270021 is a deficient number, since it is larger than the sum of its proper divisors (134411489).

823270021 is a wasteful number, since it uses less digits than its factorization.

823270021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16801443 (or 16801436 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 823270021 is about 28692.6823597934. The cubic root of 823270021 is about 937.2327021307.

The spelling of 823270021 in words is "eight hundred twenty-three million, two hundred seventy thousand, twenty-one".