6643699072 has 16 divisors (see below), whose sum is σ = 13235494500. Its totient is φ = 3321849472.

The previous prime is 6643699037. The next prime is 6643699079. The reversal of 6643699072 is 2709963466.

It is a tau number, because it is divible by the number of its divisors (16).

It is a super-2 number, since 2×6643699072² = 88277474718587322368, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6643699079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25951822 + ... + 25952077.

Almost surely, 2^6643699072 is an apocalyptic number.

It is an amenable number.

6643699072 is a deficient number, since it is larger than the sum of its proper divisors (6591795428).

6643699072 is an equidigital number, since it uses as much as digits as its factorization.

6643699072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51903913 (or 51903901 counting only the distinct ones).

The product of its (nonzero) digits is 2939328, while the sum is 52.

The square root of 6643699072 is about 81508.8895274620. The cubic root of 6643699072 is about 1879.9082375613.

The spelling of 6643699072 in words is "six billion, six hundred forty-three million, six hundred ninety-nine thousand, seventy-two".