638042707 has 8 divisors (see below), whose sum is σ = 647503200. Its totient is φ = 628595520.

The previous prime is 638042681. The next prime is 638042723. The reversal of 638042707 is 707240836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638042707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638042767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134919 + ... + 139567.

It is an arithmetic number, because the mean of its divisors is an integer number (80937900).

Almost surely, 2^638042707 is an apocalyptic number.

638042707 is a deficient number, since it is larger than the sum of its proper divisors (9460493).

638042707 is a wasteful number, since it uses less digits than its factorization.

638042707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6653.

The product of its (nonzero) digits is 56448, while the sum is 37.

The square root of 638042707 is about 25259.5072596438. The cubic root of 638042707 is about 860.8944664248.

The spelling of 638042707 in words is "six hundred thirty-eight million, forty-two thousand, seven hundred seven".