278720587631 has 2 divisors, whose sum is σ = 278720587632. Its totient is φ = 278720587630.

The previous prime is 278720587597. The next prime is 278720587661. The reversal of 278720587631 is 136785027872.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 278720587631 - 2⁶ = 278720587567 is a prime.

It is a super-2 number, since 2×278720587631² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (278720587661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139360293815 + 139360293816.

It is an arithmetic number, because the mean of its divisors is an integer number (139360293816).

Almost surely, 2^278720587631 is an apocalyptic number.

278720587631 is a deficient number, since it is larger than the sum of its proper divisors (1).

278720587631 is an equidigital number, since it uses as much as digits as its factorization.

278720587631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7902720, while the sum is 56.

The spelling of 278720587631 in words is "two hundred seventy-eight billion, seven hundred twenty million, five hundred eighty-seven thousand, six hundred thirty-one".