638128695274560 has 896 divisors, whose sum is σ = 2709965193216000. Its totient is φ = 141152870799360.

The previous prime is 638128695274519. The next prime is 638128695274703. The reversal of 638128695274560 is 65472596821836.

638128695274560 is a `hidden beast` number, since 6 + 3 + 8 + 1 + 2 + 8 + 6 + 9 + 52 + 7 + 4 + 560 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 88396089 + ... + 95342151.

It is a 1-persistent number, because it is pandigital, but 2⋅638128695274560 = 1276257390549120 is not.

Almost surely, 2^{638128695274560} is an apocalyptic number.

638128695274560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638128695274560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1354982596608000).

638128695274560 is an abundant number, since it is smaller than the sum of its proper divisors (2071836497941440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638128695274560 is a wasteful number, since it uses less digits than its factorization.

638128695274560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6946141 (or 6946111 counting only the distinct ones).

The product of its (nonzero) digits is 1045094400, while the sum is 72.

The spelling of 638128695274560 in words is "six hundred thirty-eight trillion, one hundred twenty-eight billion, six hundred ninety-five million, two hundred seventy-four thousand, five hundred sixty".