1638307774852 has 72 divisors (see below), whose sum is σ = 3350944583448. Its totient is φ = 698805273600.

The previous prime is 1638307774849. The next prime is 1638307774861. The reversal of 1638307774852 is 2584777038361.

It can be written as a sum of positive squares in 4 ways, for example, as 76847601796 + 1561460173056 = 277214^2 + 1249584^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 87896878 + ... + 87915514.

Almost surely, 2^{1638307774852} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1638307774852, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1675472291724).

1638307774852 is an abundant number, since it is smaller than the sum of its proper divisors (1712636808596).

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

1638307774852 is a wasteful number, since it uses less digits than its factorization.

1638307774852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20757 (or 20748 counting only the distinct ones).

The product of its (nonzero) digits is 47416320, while the sum is 61.

The spelling of 1638307774852 in words is "one trillion, six hundred thirty-eight billion, three hundred seven million, seven hundred seventy-four thousand, eight hundred fifty-two".