397663521 has 24 divisors (see below), whose sum is σ = 561441600. Its totient is φ = 250327584.

The previous prime is 397663493. The next prime is 397663523. The reversal of 397663521 is 125366793.

It is not a de Polignac number, because 397663521 - 2¹⁰ = 397662497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (397663523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 648411 + ... + 649023.

It is an arithmetic number, because the mean of its divisors is an integer number (23393400).

Almost surely, 2^397663521 is an apocalyptic number.

It is an amenable number.

397663521 is a deficient number, since it is larger than the sum of its proper divisors (163778079).

397663521 is a wasteful number, since it uses less digits than its factorization.

397663521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1253 (or 1234 counting only the distinct ones).

The product of its digits is 204120, while the sum is 42.

The square root of 397663521 is about 19941.5024759921. The cubic root of 397663521 is about 735.3688869753.

The spelling of 397663521 in words is "three hundred ninety-seven million, six hundred sixty-three thousand, five hundred twenty-one".