400979987 has 4 divisors (see below), whose sum is σ = 401124360. Its totient is φ = 400835616.

The previous prime is 400979939. The next prime is 400980017. The reversal of 400979987 is 789979004.

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 400979987 - 2⁶ = 400979923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400972987) 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, 67937 + ... + 73602.

It is an arithmetic number, because the mean of its divisors is an integer number (100281090).

Almost surely, 2^400979987 is an apocalyptic number.

400979987 is a deficient number, since it is larger than the sum of its proper divisors (144373).

400979987 is a wasteful number, since it uses less digits than its factorization.

400979987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144372.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The square root of 400979987 is about 20024.4846875019. The cubic root of 400979987 is about 737.4075261627.

The spelling of 400979987 in words is "four hundred million, nine hundred seventy-nine thousand, nine hundred eighty-seven".