6399644470 has 16 divisors (see below), whose sum is σ = 11558680560. Its totient is φ = 2551119904.

The previous prime is 6399644423. The next prime is 6399644483. The reversal of 6399644470 is 744469936.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1089160 + ... + 1095019.

It is an arithmetic number, because the mean of its divisors is an integer number (722417535).

Almost surely, 2^6399644470 is an apocalyptic number.

6399644470 is a deficient number, since it is larger than the sum of its proper divisors (5159036090).

6399644470 is a wasteful number, since it uses less digits than its factorization.

6399644470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2184479.

The product of its (nonzero) digits is 3919104, while the sum is 52.

The square root of 6399644470 is about 79997.7779066394. Note that the first 3 decimals coincide. The cubic root of 6399644470 is about 1856.6011531402.

The spelling of 6399644470 in words is "six billion, three hundred ninety-nine million, six hundred forty-four thousand, four hundred seventy".