405978879 has 4 divisors (see below), whose sum is σ = 541305176. Its totient is φ = 270652584.

The previous prime is 405978869. The next prime is 405978889. The reversal of 405978879 is 978879504.

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 (405978869) and next prime (405978889).

It is not a de Polignac number, because 405978879 - 2⁵ = 405978847 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 (405978869) 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, 67663144 + ... + 67663149.

It is an arithmetic number, because the mean of its divisors is an integer number (135326294).

Almost surely, 2^405978879 is an apocalyptic number.

405978879 is a deficient number, since it is larger than the sum of its proper divisors (135326297).

405978879 is a wasteful number, since it uses less digits than its factorization.

405978879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135326296.

The product of its (nonzero) digits is 5080320, while the sum is 57.

The square root of 405978879 is about 20148.9175639785. The cubic root of 405978879 is about 740.4592225090.

The spelling of 405978879 in words is "four hundred five million, nine hundred seventy-eight thousand, eight hundred seventy-nine".