278626055021 has 2 divisors, whose sum is σ = 278626055022. Its totient is φ = 278626055020.

The previous prime is 278626054961. The next prime is 278626055023. The reversal of 278626055021 is 120550626872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 219950682121 + 58675372900 = 468989^2 + 242230^2 .

It is a cyclic number.

It is not a de Polignac number, because 278626055021 - 2²² = 278621860717 is a prime.

Together with 278626055023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278626055023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139313027510 + 139313027511.

It is an arithmetic number, because the mean of its divisors is an integer number (139313027511).

Almost surely, 2^278626055021 is an apocalyptic number.

It is an amenable number.

278626055021 is a deficient number, since it is larger than the sum of its proper divisors (1).

278626055021 is an equidigital number, since it uses as much as digits as its factorization.

278626055021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 403200, while the sum is 44.

The spelling of 278626055021 in words is "two hundred seventy-eight billion, six hundred twenty-six million, fifty-five thousand, twenty-one".