278088961 has 2 divisors, whose sum is σ = 278088962. Its totient is φ = 278088960.

The previous prime is 278088953. The next prime is 278088971. The reversal of 278088961 is 169880872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 267649600 + 10439361 = 16360^2 + 3231^2 .

It is a cyclic number.

It is not a de Polignac number, because 278088961 - 2³ = 278088953 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (278088931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139044480 + 139044481.

It is an arithmetic number, because the mean of its divisors is an integer number (139044481).

Almost surely, 2^278088961 is an apocalyptic number.

It is an amenable number.

278088961 is a deficient number, since it is larger than the sum of its proper divisors (1).

278088961 is an equidigital number, since it uses as much as digits as its factorization.

278088961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 387072, while the sum is 49.

The square root of 278088961 is about 16675.9995502519. Note that the first 3 decimals coincide. The cubic root of 278088961 is about 652.7214974937.

The spelling of 278088961 in words is "two hundred seventy-eight million, eighty-eight thousand, nine hundred sixty-one".