280115978 has 4 divisors (see below), whose sum is σ = 420173970. Its totient is φ = 140057988.

The previous prime is 280115923. The next prime is 280115981. The reversal of 280115978 is 879511082.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 185967769 + 94148209 = 13637^2 + 9703^2 .

It is a super-2 number, since 2×280115978² = 156929922261792968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 70028993 + ... + 70028996.

Almost surely, 2^280115978 is an apocalyptic number.

280115978 is a deficient number, since it is larger than the sum of its proper divisors (140057992).

280115978 is a wasteful number, since it uses less digits than its factorization.

280115978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140057991.

The product of its (nonzero) digits is 40320, while the sum is 41.

The square root of 280115978 is about 16736.6656774879. The cubic root of 280115978 is about 654.3035761713.

The spelling of 280115978 in words is "two hundred eighty million, one hundred fifteen thousand, nine hundred seventy-eight".