6642640400 has 120 divisors (see below), whose sum is σ = 17466182688. Its totient is φ = 2407680000.

The previous prime is 6642640393. The next prime is 6642640421. The reversal of 6642640400 is 40462466.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1454120 + ... + 1458680.

Almost surely, 2^6642640400 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6642640400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8733091344).

6642640400 is an abundant number, since it is smaller than the sum of its proper divisors (10823542288).

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

6642640400 is a wasteful number, since it uses less digits than its factorization.

6642640400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4921 (or 4910 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 32.

The square root of 6642640400 is about 81502.3950568325. The cubic root of 6642640400 is about 1879.8083779342.

The spelling of 6642640400 in words is "six billion, six hundred forty-two million, six hundred forty thousand, four hundred".