397891501 has 4 divisors (see below), whose sum is σ = 454733152. Its totient is φ = 341049852.

The previous prime is 397891489. The next prime is 397891517. The reversal of 397891501 is 105198793.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 397891501 - 2¹⁵ = 397858733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397891561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28420815 + ... + 28420828.

It is an arithmetic number, because the mean of its divisors is an integer number (113683288).

Almost surely, 2^397891501 is an apocalyptic number.

It is an amenable number.

397891501 is a deficient number, since it is larger than the sum of its proper divisors (56841651).

397891501 is an equidigital number, since it uses as much as digits as its factorization.

397891501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56841650.

The product of its (nonzero) digits is 68040, while the sum is 43.

The square root of 397891501 is about 19947.2178761851. The cubic root of 397891501 is about 735.5093888171.

The spelling of 397891501 in words is "three hundred ninety-seven million, eight hundred ninety-one thousand, five hundred one".