999278863 has 16 divisors (see below), whose sum is σ = 1101864960. Its totient is φ = 906178680.

The previous prime is 999278857. The next prime is 999278879. The reversal of 999278863 is 368872999.

It is a happy number.

It is not a de Polignac number, because 999278863 - 2²¹ = 997181711 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 (999278843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 780658 + ... + 781936.

It is an arithmetic number, because the mean of its divisors is an integer number (68866560).

Almost surely, 2^999278863 is an apocalyptic number.

999278863 is a deficient number, since it is larger than the sum of its proper divisors (102586097).

999278863 is a wasteful number, since it uses less digits than its factorization.

With its successor (999278864) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (1899).

999278863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1899 (or 1877 counting only the distinct ones).

The product of its digits is 11757312, while the sum is 61.

The square root of 999278863 is about 31611.3723681842. The cubic root of 999278863 is about 999.7595631948.

The spelling of 999278863 in words is "nine hundred ninety-nine million, two hundred seventy-eight thousand, eight hundred sixty-three".