6640369644 has 12 divisors (see below), whose sum is σ = 15494195864. Its totient is φ = 2213456544.

The previous prime is 6640369607. The next prime is 6640369661. The reversal of 6640369644 is 4469630466.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 6640369593 and 6640369602.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 276682057 + ... + 276682080.

Almost surely, 2^6640369644 is an apocalyptic number.

It is an amenable number.

6640369644 is an abundant number, since it is smaller than the sum of its proper divisors (8853826220).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6640369644 is a wasteful number, since it uses less digits than its factorization.

6640369644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553364144 (or 553364142 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 48.

The square root of 6640369644 is about 81488.4632570771. The cubic root of 6640369644 is about 1879.5941522454.

The spelling of 6640369644 in words is "six billion, six hundred forty million, three hundred sixty-nine thousand, six hundred forty-four".