397221973 has 4 divisors (see below), whose sum is σ = 407957740. Its totient is φ = 386486208.

The previous prime is 397221971. The next prime is 397221989. The reversal of 397221973 is 379122793.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 379122793 = 7 ⋅54160399.

It can be written as a sum of positive squares in 2 ways, for example, as 175748049 + 221473924 = 13257^2 + 14882^2 .

It is a cyclic number.

It is not a de Polignac number, because 397221973 - 2¹ = 397221971 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 (397221971) 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, 5367828 + ... + 5367901.

It is an arithmetic number, because the mean of its divisors is an integer number (101989435).

Almost surely, 2^397221973 is an apocalyptic number.

It is an amenable number.

397221973 is a deficient number, since it is larger than the sum of its proper divisors (10735767).

397221973 is a wasteful number, since it uses less digits than its factorization.

397221973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10735766.

The product of its digits is 142884, while the sum is 43.

The square root of 397221973 is about 19930.4283195319. The cubic root of 397221973 is about 735.0966124718.

The spelling of 397221973 in words is "three hundred ninety-seven million, two hundred twenty-one thousand, nine hundred seventy-three".