6642514640 has 40 divisors (see below), whose sum is σ = 15471677160. Its totient is φ = 2652217856.

The previous prime is 6642514639. The next prime is 6642514649. The reversal of 6642514640 is 464152466.

It can be written as a sum of positive squares in 4 ways, for example, as 8737936 + 6633776704 = 2956^2 + 81448^2 .

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

It is a super-2 number, since 2×6642514640² = 88246001485228659200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 6642514594 and 6642514603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6642514649) 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, 29975 + ... + 119094.

It is an arithmetic number, because the mean of its divisors is an integer number (386791929).

Almost surely, 2^6642514640 is an apocalyptic number.

It is an amenable number.

6642514640 is an abundant number, since it is smaller than the sum of its proper divisors (8829162520).

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

6642514640 is a wasteful number, since it uses less digits than its factorization.

6642514640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149639 (or 149633 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 38.

The square root of 6642514640 is about 81501.6235421111. The cubic root of 6642514640 is about 1879.7965148707.

The spelling of 6642514640 in words is "six billion, six hundred forty-two million, five hundred fourteen thousand, six hundred forty".