278961131 has 2 divisors, whose sum is σ = 278961132. Its totient is φ = 278961130.

The previous prime is 278961119. The next prime is 278961161. The reversal of 278961131 is 131169872.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 278961131 - 2¹⁰ = 278960107 is a prime.

It is a super-2 number, since 2×278961131² = 155638625217598322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (278961161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139480565 + 139480566.

It is an arithmetic number, because the mean of its divisors is an integer number (139480566).

Almost surely, 2^278961131 is an apocalyptic number.

278961131 is a deficient number, since it is larger than the sum of its proper divisors (1).

278961131 is an equidigital number, since it uses as much as digits as its factorization.

278961131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 38.

The square root of 278961131 is about 16702.1295348827. The cubic root of 278961131 is about 653.4031618467.

The spelling of 278961131 in words is "two hundred seventy-eight million, nine hundred sixty-one thousand, one hundred thirty-one".