6643978750 has 40 divisors (see below), whose sum is σ = 12718553760. Its totient is φ = 2601024000.

The previous prime is 6643978727. The next prime is 6643978753. The reversal of 6643978750 is 578793466.

It is a happy number.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 6643978691 and 6643978700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643978753) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2206 + ... + 115294.

It is an arithmetic number, because the mean of its divisors is an integer number (317963844).

Almost surely, 2^6643978750 is an apocalyptic number.

6643978750 is a deficient number, since it is larger than the sum of its proper divisors (6074575010).

6643978750 is a wasteful number, since it uses less digits than its factorization.

6643978750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113158 (or 113143 counting only the distinct ones).

The product of its (nonzero) digits is 7620480, while the sum is 55.

The square root of 6643978750 is about 81510.6051382273. The cubic root of 6643978750 is about 1879.9346165204.

The spelling of 6643978750 in words is "six billion, six hundred forty-three million, nine hundred seventy-eight thousand, seven hundred fifty".