401397979 has 4 divisors (see below), whose sum is σ = 401549400. Its totient is φ = 401246560.

The previous prime is 401397977. The next prime is 401397989. The reversal of 401397979 is 979793104.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 401397979 - 2¹ = 401397977 is a prime.

It is a super-2 number, since 2×401397979² = 322240675090568882, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (401397977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71662 + ... + 77059.

It is an arithmetic number, because the mean of its divisors is an integer number (100387350).

Almost surely, 2^401397979 is an apocalyptic number.

401397979 is a deficient number, since it is larger than the sum of its proper divisors (151421).

401397979 is a wasteful number, since it uses less digits than its factorization.

401397979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151420.

The product of its (nonzero) digits is 428652, while the sum is 49.

The square root of 401397979 is about 20034.9189916006. The cubic root of 401397979 is about 737.6636681284.

The spelling of 401397979 in words is "four hundred one million, three hundred ninety-seven thousand, nine hundred seventy-nine".