3688878721 has 24 divisors (see below), whose sum is σ = 4098528000. Its totient is φ = 3317529600.

The previous prime is 3688878701. The next prime is 3688878731. The reversal of 3688878721 is 1278788863.

It is a happy number.

It is not a de Polignac number, because 3688878721 - 2¹¹ = 3688876673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3688878701) 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 in 23 ways as a sum of consecutive naturals, for example, 5754561 + ... + 5755201.

It is an arithmetic number, because the mean of its divisors is an integer number (170772000).

Almost surely, 2^3688878721 is an apocalyptic number.

It is an amenable number.

3688878721 is a deficient number, since it is larger than the sum of its proper divisors (409649279).

3688878721 is a wasteful number, since it uses less digits than its factorization.

3688878721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101 (or 1090 counting only the distinct ones).

The product of its digits is 7225344, while the sum is 58.

The square root of 3688878721 is about 60736.1401555943. The cubic root of 3688878721 is about 1545.1291731562.

The spelling of 3688878721 in words is "three billion, six hundred eighty-eight million, eight hundred seventy-eight thousand, seven hundred twenty-one".