397281891 has 8 divisors (see below), whose sum is σ = 560868624. Its totient is φ = 249274880.

The previous prime is 397281889. The next prime is 397281917. The reversal of 397281891 is 198182793.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 397281891 - 2¹ = 397281889 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 397281891.

It is not an unprimeable number, because it can be changed into a prime (397281881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3894870 + ... + 3894971.

It is an arithmetic number, because the mean of its divisors is an integer number (70108578).

Almost surely, 2^397281891 is an apocalyptic number.

397281891 is a deficient number, since it is larger than the sum of its proper divisors (163586733).

397281891 is a wasteful number, since it uses less digits than its factorization.

397281891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7789861.

The product of its digits is 217728, while the sum is 48.

The square root of 397281891 is about 19931.9314417846. The cubic root of 397281891 is about 735.1335719112.

The spelling of 397281891 in words is "three hundred ninety-seven million, two hundred eighty-one thousand, eight hundred ninety-one".