638578601 has 4 divisors (see below), whose sum is σ = 666342912. Its totient is φ = 610814292.

The previous prime is 638578559. The next prime is 638578607. The reversal of 638578601 is 106875836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 638578601 - 2¹⁴ = 638562217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638578607) 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, 13882121 + ... + 13882166.

It is an arithmetic number, because the mean of its divisors is an integer number (166585728).

Almost surely, 2^638578601 is an apocalyptic number.

It is an amenable number.

638578601 is a deficient number, since it is larger than the sum of its proper divisors (27764311).

638578601 is a wasteful number, since it uses less digits than its factorization.

638578601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27764310.

The product of its (nonzero) digits is 241920, while the sum is 44.

The square root of 638578601 is about 25270.1128014894. The cubic root of 638578601 is about 861.1354216000.

The spelling of 638578601 in words is "six hundred thirty-eight million, five hundred seventy-eight thousand, six hundred one".