278961493 has 2 divisors, whose sum is σ = 278961494. Its totient is φ = 278961492.

The previous prime is 278961443. The next prime is 278961509. The reversal of 278961493 is 394169872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204432804 + 74528689 = 14298^2 + 8633^2 .

It is a cyclic number.

It is not a de Polignac number, because 278961493 - 2²⁵ = 245407061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278961413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139480746 + 139480747.

It is an arithmetic number, because the mean of its divisors is an integer number (139480747).

Almost surely, 2^278961493 is an apocalyptic number.

It is an amenable number.

278961493 is a deficient number, since it is larger than the sum of its proper divisors (1).

278961493 is an equidigital number, since it uses as much as digits as its factorization.

278961493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 49.

The square root of 278961493 is about 16702.1403718206. The cubic root of 278961493 is about 653.4034444808.

The spelling of 278961493 in words is "two hundred seventy-eight million, nine hundred sixty-one thousand, four hundred ninety-three".