278818655681 has 16 divisors (see below), whose sum is σ = 314609785344. Its totient is φ = 245667485184.

The previous prime is 278818655657. The next prime is 278818655737. The reversal of 278818655681 is 186556818872.

It is not a de Polignac number, because 278818655681 - 2¹⁰ = 278818654657 is a prime.

It is a super-2 number, since 2×278818655681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (278818655641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7567700 + ... + 7604453.

It is an arithmetic number, because the mean of its divisors is an integer number (19663111584).

Almost surely, 2^278818655681 is an apocalyptic number.

It is an amenable number.

278818655681 is a deficient number, since it is larger than the sum of its proper divisors (35791129663).

278818655681 is a wasteful number, since it uses less digits than its factorization.

278818655681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15172240.

The product of its digits is 51609600, while the sum is 65.

The spelling of 278818655681 in words is "two hundred seventy-eight billion, eight hundred eighteen million, six hundred fifty-five thousand, six hundred eighty-one".