1638253674 has 80 divisors (see below), whose sum is σ = 3834151200. Its totient is φ = 522166176.

The previous prime is 1638253627. The next prime is 1638253679. The reversal of 1638253674 is 4763528361.

1638253674 is a `hidden beast` number, since 1 + 638 + 2 + 5 + 3 + 6 + 7 + 4 = 666.

It is not an unprimeable number, because it can be changed into a prime (1638253679) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 501057 + ... + 504315.

It is an arithmetic number, because the mean of its divisors is an integer number (47926890).

Almost surely, 2^1638253674 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1638253674, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1917075600).

1638253674 is an abundant number, since it is smaller than the sum of its proper divisors (2195897526).

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

1638253674 is a wasteful number, since it uses less digits than its factorization.

1638253674 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3409 (or 3400 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 1638253674 is about 40475.3464963550. The cubic root of 1638253674 is about 1178.8549828434.

The spelling of 1638253674 in words is "one billion, six hundred thirty-eight million, two hundred fifty-three thousand, six hundred seventy-four".