278697978 has 48 divisors (see below), whose sum is σ = 656431776. Its totient is φ = 84944160.

The previous prime is 278697973. The next prime is 278697997. The reversal of 278697978 is 879796872.

It is a super-4 number, since 4×278697978⁴ (a number of 35 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (278697971) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19473 + ... + 30603.

It is an arithmetic number, because the mean of its divisors is an integer number (13675662).

Almost surely, 2^278697978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 278697978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (328215888).

278697978 is an abundant number, since it is smaller than the sum of its proper divisors (377733798).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

278697978 is a wasteful number, since it uses less digits than its factorization.

278697978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11259 (or 11256 counting only the distinct ones).

The product of its digits is 21337344, while the sum is 63.

The square root of 278697978 is about 16694.2498483759. The cubic root of 278697978 is about 653.1976384737.

The spelling of 278697978 in words is "two hundred seventy-eight million, six hundred ninety-seven thousand, nine hundred seventy-eight".