1878668661 has 8 divisors (see below), whose sum is σ = 2507719104. Its totient is φ = 1251032000.

The previous prime is 1878668621. The next prime is 1878668669. The reversal of 1878668661 is 1668668781.

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

It is a cyclic number.

It is not a de Polignac number, because 1878668661 - 2²¹ = 1876571509 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1878668669) 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, 350340 + ... + 355661.

It is an arithmetic number, because the mean of its divisors is an integer number (313464888).

Almost surely, 2^1878668661 is an apocalyptic number.

It is an amenable number.

1878668661 is a deficient number, since it is larger than the sum of its proper divisors (629050443).

1878668661 is an equidigital number, since it uses as much as digits as its factorization.

1878668661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706891.

The product of its digits is 4644864, while the sum is 57.

The square root of 1878668661 is about 43343.6115361884. The cubic root of 1878668661 is about 1233.9097528537.

The spelling of 1878668661 in words is "one billion, eight hundred seventy-eight million, six hundred sixty-eight thousand, six hundred sixty-one".