638609579 has 8 divisors (see below), whose sum is σ = 665613312. Its totient is φ = 612006120.

The previous prime is 638609533. The next prime is 638609591. The reversal of 638609579 is 975906836.

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

It is a cyclic number.

It is not a de Polignac number, because 638609579 - 2¹⁶ = 638544043 is a prime.

It is a Duffinian number.

638609579 is a modest number, since divided by 9579 gives 6386 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 638609579.

It is not an unprimeable number, because it can be changed into a prime (638609519) 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, 96809 + ... + 103194.

It is an arithmetic number, because the mean of its divisors is an integer number (83201664).

Almost surely, 2^638609579 is an apocalyptic number.

638609579 is a deficient number, since it is larger than the sum of its proper divisors (27003733).

638609579 is a wasteful number, since it uses less digits than its factorization.

638609579 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200137.

The product of its (nonzero) digits is 2449440, while the sum is 53.

The square root of 638609579 is about 25270.7257315654. The cubic root of 638609579 is about 861.1493461828.

The spelling of 638609579 in words is "six hundred thirty-eight million, six hundred nine thousand, five hundred seventy-nine".