397194721 has 24 divisors (see below), whose sum is σ = 504004032. Its totient is φ = 306372000.

The previous prime is 397194719. The next prime is 397194731. The reversal of 397194721 is 127491793.

It is a happy number.

It is not a de Polignac number, because 397194721 - 2¹ = 397194719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (397194731) 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 23 ways as a sum of consecutive naturals, for example, 83226 + ... + 87868.

It is an arithmetic number, because the mean of its divisors is an integer number (21000168).

Almost surely, 2^397194721 is an apocalyptic number.

It is an amenable number.

397194721 is a deficient number, since it is larger than the sum of its proper divisors (106809311).

397194721 is a wasteful number, since it uses less digits than its factorization.

397194721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4773 (or 4762 counting only the distinct ones).

The product of its digits is 95256, while the sum is 43.

The square root of 397194721 is about 19929.7446295732. The cubic root of 397194721 is about 735.0798012911.

The spelling of 397194721 in words is "three hundred ninety-seven million, one hundred ninety-four thousand, seven hundred twenty-one".