638445281078 has 16 divisors (see below), whose sum is σ = 1045146122496. Its totient is φ = 290086433640.

The previous prime is 638445281069. The next prime is 638445281083. The reversal of 638445281078 is 870182544836.

It is a super-2 number, since 2×638445281078² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5742026 + ... + 5852157.

It is an arithmetic number, because the mean of its divisors is an integer number (65321632656).

Almost surely, 2^638445281078 is an apocalyptic number.

638445281078 is a deficient number, since it is larger than the sum of its proper divisors (406700841418).

638445281078 is a wasteful number, since it uses less digits than its factorization.

638445281078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11596699.

The product of its (nonzero) digits is 10321920, while the sum is 56.

The spelling of 638445281078 in words is "six hundred thirty-eight billion, four hundred forty-five million, two hundred eighty-one thousand, seventy-eight".