278641945 has 16 divisors (see below), whose sum is σ = 347655168. Its totient is φ = 214220160.

The previous prime is 278641921. The next prime is 278641969. The reversal of 278641945 is 549146872.

It is an interprime number because it is at equal distance from previous prime (278641921) and next prime (278641969).

It is a de Polignac number, because none of the positive numbers 2^k-278641945 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 278641895 and 278641904.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3592 + ... + 23878.

It is an arithmetic number, because the mean of its divisors is an integer number (21728448).

Almost surely, 2^278641945 is an apocalyptic number.

It is an amenable number.

278641945 is a deficient number, since it is larger than the sum of its proper divisors (69013223).

278641945 is a wasteful number, since it uses less digits than its factorization.

278641945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20400.

The product of its digits is 483840, while the sum is 46.

The square root of 278641945 is about 16692.5715514417. The cubic root of 278641945 is about 653.1538598085.

The spelling of 278641945 in words is "two hundred seventy-eight million, six hundred forty-one thousand, nine hundred forty-five".