397680691 has 4 divisors (see below), whose sum is σ = 397747800. Its totient is φ = 397613584.

The previous prime is 397680671. The next prime is 397680719. The reversal of 397680691 is 196086793.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 397680691 - 2¹¹ = 397678643 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (397680671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23701 + ... + 36838.

It is an arithmetic number, because the mean of its divisors is an integer number (99436950).

Almost surely, 2^397680691 is an apocalyptic number.

397680691 is a deficient number, since it is larger than the sum of its proper divisors (67109).

397680691 is an equidigital number, since it uses as much as digits as its factorization.

397680691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67108.

The product of its (nonzero) digits is 489888, while the sum is 49.

The square root of 397680691 is about 19941.9329805313. The cubic root of 397680691 is about 735.3794705478.

The spelling of 397680691 in words is "three hundred ninety-seven million, six hundred eighty thousand, six hundred ninety-one".