638242144 has 24 divisors (see below), whose sum is σ = 1260356328. Its totient is φ = 318151680.

The previous prime is 638242141. The next prime is 638242147. The reversal of 638242144 is 441242836.

It is an interprime number because it is at equal distance from previous prime (638242141) and next prime (638242147).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638242141) 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, 19537 + ... + 40720.

It is an arithmetic number, because the mean of its divisors is an integer number (52514847).

Almost surely, 2^638242144 is an apocalyptic number.

It is an amenable number.

638242144 is a deficient number, since it is larger than the sum of its proper divisors (622114184).

638242144 is a wasteful number, since it uses less digits than its factorization.

638242144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60598 (or 60590 counting only the distinct ones).

The product of its digits is 36864, while the sum is 34.

The square root of 638242144 is about 25263.4547122914. The cubic root of 638242144 is about 860.9841554700.

The spelling of 638242144 in words is "six hundred thirty-eight million, two hundred forty-two thousand, one hundred forty-four".