6639001000 has 32 divisors (see below), whose sum is σ = 15535264680. Its totient is φ = 2655600000.

The previous prime is 6639000997. The next prime is 6639001003. The reversal of 6639001000 is 1009366.

It is an interprime number because it is at equal distance from previous prime (6639000997) and next prime (6639001003).

It can be written as a sum of positive squares in 4 ways, for example, as 2693402404 + 3945598596 = 51898^2 + 62814^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (6639001003) 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, 3318501 + ... + 3320500.

Almost surely, 2^6639001000 is an apocalyptic number.

It is an amenable number.

6639001000 is an abundant number, since it is smaller than the sum of its proper divisors (8896263680).

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

6639001000 is a wasteful number, since it uses less digits than its factorization.

6639001000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6639022 (or 6639008 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 6639001000 is about 81480.0650466112. The cubic root of 6639001000 is about 1879.4650092330.

The spelling of 6639001000 in words is "six billion, six hundred thirty-nine million, one thousand".