6639401003 has 4 divisors (see below), whose sum is σ = 6639599760. Its totient is φ = 6639202248.

The previous prime is 6639400991. The next prime is 6639401071. The reversal of 6639401003 is 3001049366.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6639401003 - 2⁴ = 6639400987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6639401803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35648 + ... + 120621.

It is an arithmetic number, because the mean of its divisors is an integer number (1659899940).

Almost surely, 2^6639401003 is an apocalyptic number.

6639401003 is a deficient number, since it is larger than the sum of its proper divisors (198757).

6639401003 is a wasteful number, since it uses less digits than its factorization.

6639401003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198756.

The product of its (nonzero) digits is 11664, while the sum is 32.

The square root of 6639401003 is about 81482.5196161729. The cubic root of 6639401003 is about 1879.5027546983.

The spelling of 6639401003 in words is "six billion, six hundred thirty-nine million, four hundred one thousand, three".