278661879 has 12 divisors (see below), whose sum is σ = 406205800. Its totient is φ = 184069584.

The previous prime is 278661869. The next prime is 278661881. The reversal of 278661879 is 978166872.

It is not a de Polignac number, because 278661879 - 2²⁸ = 10226423 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 (278661829) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 141049 + ... + 143010.

Almost surely, 2^278661879 is an apocalyptic number.

278661879 is a deficient number, since it is larger than the sum of its proper divisors (127543921).

278661879 is a wasteful number, since it uses less digits than its factorization.

278661879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284174 (or 284171 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 54.

The square root of 278661879 is about 16693.1686327072. The cubic root of 278661879 is about 653.1694349445.

The spelling of 278661879 in words is "two hundred seventy-eight million, six hundred sixty-one thousand, eight hundred seventy-nine".