278861854661 has 8 divisors (see below), whose sum is σ = 316118701920. Its totient is φ = 243862998192.

The previous prime is 278861854639. The next prime is 278861854693. The reversal of 278861854661 is 166458168872.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-278861854661 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 278861854594 and 278861854603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278861856661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 564497435 + ... + 564497928.

It is an arithmetic number, because the mean of its divisors is an integer number (39514837740).

Almost surely, 2^278861854661 is an apocalyptic number.

It is an amenable number.

278861854661 is a deficient number, since it is larger than the sum of its proper divisors (37256847259).

278861854661 is a wasteful number, since it uses less digits than its factorization.

278861854661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1128995395.

The product of its digits is 30965760, while the sum is 62.

The spelling of 278861854661 in words is "two hundred seventy-eight billion, eight hundred sixty-one million, eight hundred fifty-four thousand, six hundred sixty-one".