397979642 has 4 divisors (see below), whose sum is σ = 596969466. Its totient is φ = 198989820.

The previous prime is 397979629. The next prime is 397979669. The reversal of 397979642 is 246979793.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 246979793 = 6269 ⋅39397.

It can be written as a sum of positive squares in only one way, i.e., 392079601 + 5900041 = 19801^2 + 2429^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99494909 + ... + 99494912.

Almost surely, 2^397979642 is an apocalyptic number.

397979642 is a deficient number, since it is larger than the sum of its proper divisors (198989824).

397979642 is a wasteful number, since it uses less digits than its factorization.

397979642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198989823.

The product of its digits is 5143824, while the sum is 56.

The square root of 397979642 is about 19949.4271095688. The cubic root of 397979642 is about 735.5636948666.

The spelling of 397979642 in words is "three hundred ninety-seven million, nine hundred seventy-nine thousand, six hundred forty-two".