278751026681 has 2 divisors, whose sum is σ = 278751026682. Its totient is φ = 278751026680.

The previous prime is 278751026677. The next prime is 278751026683. The reversal of 278751026681 is 186620157872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 277640471056 + 1110555625 = 526916^2 + 33325^2 .

It is a cyclic number.

It is not a de Polignac number, because 278751026681 - 2² = 278751026677 is a prime.

It is a super-2 number, since 2×278751026681² (a number of 24 digits) contains 22 as substring.

Together with 278751026683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (278751026683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139375513340 + 139375513341.

It is an arithmetic number, because the mean of its divisors is an integer number (139375513341).

Almost surely, 2^278751026681 is an apocalyptic number.

It is an amenable number.

278751026681 is a deficient number, since it is larger than the sum of its proper divisors (1).

278751026681 is an equidigital number, since it uses as much as digits as its factorization.

278751026681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2257920, while the sum is 53.

The spelling of 278751026681 in words is "two hundred seventy-eight billion, seven hundred fifty-one million, twenty-six thousand, six hundred eighty-one".