823972397 has 12 divisors (see below), whose sum is σ = 844642260. Its totient is φ = 803781888.

The previous prime is 823972381. The next prime is 823972423. The reversal of 823972397 is 793279328.

It can be written as a sum of positive squares in 6 ways, for example, as 123787876 + 700184521 = 11126^2 + 26461^2 .

It is not a de Polignac number, because 823972397 - 2⁴ = 823972381 is a prime.

It is a super-2 number, since 2×823972397² = 1357861022035851218, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (823972307) 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, 552629 + ... + 554117.

It is an arithmetic number, because the mean of its divisors is an integer number (70386855).

Almost surely, 2^823972397 is an apocalyptic number.

It is an amenable number.

823972397 is a deficient number, since it is larger than the sum of its proper divisors (20669863).

823972397 is a wasteful number, since it uses less digits than its factorization.

823972397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1792 (or 1739 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 50.

The square root of 823972397 is about 28704.9193867532. The cubic root of 823972397 is about 937.4991609355.

The spelling of 823972397 in words is "eight hundred twenty-three million, nine hundred seventy-two thousand, three hundred ninety-seven".