401556679 has 4 divisors (see below), whose sum is σ = 401626384. Its totient is φ = 401486976.

The previous prime is 401556667. The next prime is 401556691. The reversal of 401556679 is 976655104.

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

It is an interprime number because it is at equal distance from previous prime (401556667) and next prime (401556691).

It is a cyclic number.

It is not a de Polignac number, because 401556679 - 2²¹ = 399459527 is a prime.

It is a super-2 number, since 2×401556679² = 322495532899018082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401556629) 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, 25347 + ... + 38020.

It is an arithmetic number, because the mean of its divisors is an integer number (100406596).

Almost surely, 2^401556679 is an apocalyptic number.

401556679 is the 12674-th heptagonal number.

401556679 is a deficient number, since it is larger than the sum of its proper divisors (69705).

401556679 is an equidigital number, since it uses as much as digits as its factorization.

401556679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69704.

The product of its (nonzero) digits is 226800, while the sum is 43.

The square root of 401556679 is about 20038.8791852239. The cubic root of 401556679 is about 737.7608715735.

The spelling of 401556679 in words is "four hundred one million, five hundred fifty-six thousand, six hundred seventy-nine".