6640466640 has 40 divisors (see below), whose sum is σ = 20585447328. Its totient is φ = 1770791040.

The previous prime is 6640466633. The next prime is 6640466647. The reversal of 6640466640 is 466640466.

It is an interprime number because it is at equal distance from previous prime (6640466633) and next prime (6640466647).

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 6640466592 and 6640466601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640466647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13834066 + ... + 13834545.

Almost surely, 2^6640466640 is an apocalyptic number.

6640466640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6640466640 is an abundant number, since it is smaller than the sum of its proper divisors (13944980688).

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

6640466640 is a wasteful number, since it uses less digits than its factorization.

6640466640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27668627 (or 27668621 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 42.

The square root of 6640466640 is about 81489.0584066352. The cubic root of 6640466640 is about 1879.6033039562.

The spelling of 6640466640 in words is "six billion, six hundred forty million, four hundred sixty-six thousand, six hundred forty".