253135638 has 64 divisors (see below), whose sum is σ = 648069120. Its totient is φ = 71741376.

The previous prime is 253135621. The next prime is 253135643. The reversal of 253135638 is 836531352.

253135638 is a `hidden beast` number, since 2 + 5 + 3 + 13 + 5 + 638 = 666.

253135638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 45370 + ... + 50642.

It is an arithmetic number, because the mean of its divisors is an integer number (10126080).

Almost surely, 2^253135638 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 253135638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324034560).

253135638 is an abundant number, since it is smaller than the sum of its proper divisors (394933482).

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

253135638 is a wasteful number, since it uses less digits than its factorization.

253135638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5418 (or 5412 counting only the distinct ones).

The product of its digits is 64800, while the sum is 36.

The square root of 253135638 is about 15910.2368932709. The cubic root of 253135638 is about 632.5833605180.

The spelling of 253135638 in words is "two hundred fifty-three million, one hundred thirty-five thousand, six hundred thirty-eight".