397264223521 has 15 divisors (see below), whose sum is σ = 437071839555. Its totient is φ = 361079962320.

The previous prime is 397264223513. The next prime is 397264223557. The reversal of 397264223521 is 125322462793.

The square root of 397264223521 is 630289.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 389674329121 + 7589894400 = 624239^2 + 87120^2 .

It is not a de Polignac number, because 397264223521 - 2³ = 397264223513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (397264223021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 76262365 + ... + 76267573.

It is an arithmetic number, because the mean of its divisors is an integer number (29138122637).

Almost surely, 2^397264223521 is an apocalyptic number.

397264223521 is the 630289-th square number.

397264223521 is the 315145-th centered octagonal number.

It is an amenable number.

397264223521 is a deficient number, since it is larger than the sum of its proper divisors (39807616034).

397264223521 is an frugal number, since it uses more digits than its factorization.

397264223521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10462 (or 5220 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 46.

The spelling of 397264223521 in words is "three hundred ninety-seven billion, two hundred sixty-four million, two hundred twenty-three thousand, five hundred twenty-one".