278373859781 has 4 divisors (see below), whose sum is σ = 283626196812. Its totient is φ = 273121522752.

The previous prime is 278373859727. The next prime is 278373859787. The reversal of 278373859781 is 187958373872.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 124206904900 + 154166954881 = 352430^2 + 392641^2 .

It is a cyclic number.

It is not a de Polignac number, because 278373859781 - 2¹⁸ = 278373597637 is a prime.

It is a super-2 number, since 2×278373859781² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278373859787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2626168436 + ... + 2626168541.

It is an arithmetic number, because the mean of its divisors is an integer number (70906549203).

Almost surely, 2^278373859781 is an apocalyptic number.

It is an amenable number.

278373859781 is a deficient number, since it is larger than the sum of its proper divisors (5252337031).

278373859781 is an equidigital number, since it uses as much as digits as its factorization.

278373859781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5252337030.

The product of its digits is 142248960, while the sum is 68.

The spelling of 278373859781 in words is "two hundred seventy-eight billion, three hundred seventy-three million, eight hundred fifty-nine thousand, seven hundred eighty-one".