280197561 has 16 divisors (see below), whose sum is σ = 440741888. Its totient is φ = 154947600.

The previous prime is 280197557. The next prime is 280197571. The reversal of 280197561 is 165791082.

It is not a de Polignac number, because 280197561 - 2² = 280197557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (280197521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 214555 + ... + 215856.

It is an arithmetic number, because the mean of its divisors is an integer number (27546368).

Almost surely, 2^280197561 is an apocalyptic number.

280197561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

280197561 is a deficient number, since it is larger than the sum of its proper divisors (160544327).

280197561 is a wasteful number, since it uses less digits than its factorization.

280197561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430452.

The product of its (nonzero) digits is 30240, while the sum is 39.

The square root of 280197561 is about 16739.1027537321. The cubic root of 280197561 is about 654.3670913715.

The spelling of 280197561 in words is "two hundred eighty million, one hundred ninety-seven thousand, five hundred sixty-one".