280996391 has 4 divisors (see below), whose sum is σ = 302611512. Its totient is φ = 259381272.

The previous prime is 280996379. The next prime is 280996403. The reversal of 280996391 is 193699082.

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

It is an interprime number because it is at equal distance from previous prime (280996379) and next prime (280996403).

It is a cyclic number.

It is not a de Polignac number, because 280996391 - 2⁶ = 280996327 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 (280996321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10807541 + ... + 10807566.

It is an arithmetic number, because the mean of its divisors is an integer number (75652878).

Almost surely, 2^280996391 is an apocalyptic number.

280996391 is a deficient number, since it is larger than the sum of its proper divisors (21615121).

280996391 is a wasteful number, since it uses less digits than its factorization.

280996391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21615120.

The product of its (nonzero) digits is 209952, while the sum is 47.

The square root of 280996391 is about 16762.9469664495. The cubic root of 280996391 is about 654.9883578919.

The spelling of 280996391 in words is "two hundred eighty million, nine hundred ninety-six thousand, three hundred ninety-one".