638454235378 has 8 divisors (see below), whose sum is σ = 969803902080. Its totient is φ = 315186268020.

The previous prime is 638454235373. The next prime is 638454235399. The reversal of 638454235378 is 873532454836.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (638454235373) 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, 2020424638 + ... + 2020424953.

It is an arithmetic number, because the mean of its divisors is an integer number (121225487760).

Almost surely, 2^638454235378 is an apocalyptic number.

638454235378 is a deficient number, since it is larger than the sum of its proper divisors (331349666702).

638454235378 is a wasteful number, since it uses less digits than its factorization.

638454235378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4040849672.

The product of its digits is 58060800, while the sum is 58.

The spelling of 638454235378 in words is "six hundred thirty-eight billion, four hundred fifty-four million, two hundred thirty-five thousand, three hundred seventy-eight".