638405485026 has 32 divisors (see below), whose sum is σ = 1313190335808. Its totient is φ = 206755012800.

The previous prime is 638405485009. The next prime is 638405485073. The reversal of 638405485026 is 620584504836.

638405485026 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×638405485026³ (a number of 36 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 638405485026.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1895520 + ... + 2206763.

It is an arithmetic number, because the mean of its divisors is an integer number (41037197994).

Almost surely, 2^638405485026 is an apocalyptic number.

638405485026 is an abundant number, since it is smaller than the sum of its proper divisors (674784850782).

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

638405485026 is a wasteful number, since it uses less digits than its factorization.

638405485026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4103026.

The product of its (nonzero) digits is 5529600, while the sum is 51.

The spelling of 638405485026 in words is "six hundred thirty-eight billion, four hundred five million, four hundred eighty-five thousand, twenty-six".