6640557653 has 4 divisors (see below), whose sum is σ = 6684535008. Its totient is φ = 6596580300.

The previous prime is 6640557619. The next prime is 6640557689. The reversal of 6640557653 is 3567550466.

6640557653 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6640557653 - 2⁸ = 6640557397 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6640557598 and 6640557607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640557353) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21988451 + ... + 21988752.

It is an arithmetic number, because the mean of its divisors is an integer number (1671133752).

Almost surely, 2^6640557653 is an apocalyptic number.

It is an amenable number.

6640557653 is a deficient number, since it is larger than the sum of its proper divisors (43977355).

6640557653 is a wasteful number, since it uses less digits than its factorization.

6640557653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43977354.

The product of its (nonzero) digits is 2268000, while the sum is 47.

The square root of 6640557653 is about 81489.6168416566. The cubic root of 6640557653 is about 1879.6118910813.

The spelling of 6640557653 in words is "six billion, six hundred forty million, five hundred fifty-seven thousand, six hundred fifty-three".