280855981 has 32 divisors (see below), whose sum is σ = 341913600. Its totient is φ = 225650880.

The previous prime is 280855969. The next prime is 280855987. The reversal of 280855981 is 189558082.

280855981 = T₂₈ + T₂₉ + ... + T₁₁₈₉.

It is not a de Polignac number, because 280855981 - 2¹¹ = 280853933 is a prime.

It is a super-2 number, since 2×280855981² = 157760164126944722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280855987) 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, 1330966 + ... + 1331176.

It is an arithmetic number, because the mean of its divisors is an integer number (10684800).

Almost surely, 2^280855981 is an apocalyptic number.

It is an amenable number.

280855981 is a deficient number, since it is larger than the sum of its proper divisors (61057619).

280855981 is a wasteful number, since it uses less digits than its factorization.

280855981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409.

The product of its (nonzero) digits is 230400, while the sum is 46.

The square root of 280855981 is about 16758.7583370607. The cubic root of 280855981 is about 654.8792435156.

The spelling of 280855981 in words is "two hundred eighty million, eight hundred fifty-five thousand, nine hundred eighty-one".