397680640 has 224 divisors, whose sum is σ = 1163848320. Its totient is φ = 127401984.

The previous prime is 397680637. The next prime is 397680653. The reversal of 397680640 is 46086793.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (224).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5447644 + ... + 5447716.

Almost surely, 2^397680640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 397680640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (581924160).

397680640 is an abundant number, since it is smaller than the sum of its proper divisors (766167680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

397680640 is an equidigital number, since it uses as much as digits as its factorization.

397680640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 43.

The square root of 397680640 is about 19941.9317018187. The cubic root of 397680640 is about 735.3794391119.

The spelling of 397680640 in words is "three hundred ninety-seven million, six hundred eighty thousand, six hundred forty".