397976561 has 4 divisors (see below), whose sum is σ = 398045172. Its totient is φ = 397907952.

The previous prime is 397976519. The next prime is 397976569. The reversal of 397976561 is 165679793.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165679793 = 9719 ⋅17047.

It can be written as a sum of positive squares in 2 ways, for example, as 8151025 + 389825536 = 2855^2 + 19744^2 .

It is a cyclic number.

It is not a de Polignac number, because 397976561 - 2⁶ = 397976497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (397976569) 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 3 ways as a sum of consecutive naturals, for example, 24710 + ... + 37503.

It is an arithmetic number, because the mean of its divisors is an integer number (99511293).

Almost surely, 2^397976561 is an apocalyptic number.

It is an amenable number.

397976561 is a deficient number, since it is larger than the sum of its proper divisors (68611).

397976561 is an equidigital number, since it uses as much as digits as its factorization.

397976561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68610.

The product of its digits is 2143260, while the sum is 53.

The square root of 397976561 is about 19949.3498891568. The cubic root of 397976561 is about 735.5617967146.

The spelling of 397976561 in words is "three hundred ninety-seven million, nine hundred seventy-six thousand, five hundred sixty-one".