280605978 has 64 divisors (see below), whose sum is σ = 671207040. Its totient is φ = 86572800.

The previous prime is 280605973. The next prime is 280606019. The reversal of 280605978 is 879506082.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (280605971) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53493 + ... + 58503.

It is an arithmetic number, because the mean of its divisors is an integer number (10487610).

Almost surely, 2^280605978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 280605978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (335603520).

280605978 is an abundant number, since it is smaller than the sum of its proper divisors (390601062).

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

280605978 is a wasteful number, since it uses less digits than its factorization.

280605978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5100 (or 5094 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The square root of 280605978 is about 16751.2978004691. The cubic root of 280605978 is about 654.6848729848.

The spelling of 280605978 in words is "two hundred eighty million, six hundred five thousand, nine hundred seventy-eight".