6642788490 has 96 divisors (see below), whose sum is σ = 18681783120. Its totient is φ = 1627941888.

The previous prime is 6642788473. The next prime is 6642788501. The reversal of 6642788490 is 948872466.

It can be written as a sum of positive squares in 8 ways, for example, as 5252915529 + 1389872961 = 72477^2 + 37281^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 255534 + ... + 280326.

Almost surely, 2^6642788490 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6642788490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9340891560).

6642788490 is an abundant number, since it is smaller than the sum of its proper divisors (12038994630).

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

6642788490 is a wasteful number, since it uses less digits than its factorization.

6642788490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25048 (or 25045 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 54.

The square root of 6642788490 is about 81503.3035526782. The cubic root of 6642788490 is about 1879.8223472163.

The spelling of 6642788490 in words is "six billion, six hundred forty-two million, seven hundred eighty-eight thousand, four hundred ninety".