642635136 has 384 divisors, whose sum is σ = 2245501440. Its totient is φ = 173813760.

The previous prime is 642635117. The next prime is 642635141. The reversal of 642635136 is 631536246.

642635136 is a `hidden beast` number, since 6 + 4 + 2 + 635 + 13 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 642635136.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7742551 + ... + 7742633.

It is an arithmetic number, because the mean of its divisors is an integer number (5847660).

Almost surely, 2^642635136 is an apocalyptic number.

642635136 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642635136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1122750720).

642635136 is an abundant number, since it is smaller than the sum of its proper divisors (1602866304).

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

642635136 is a wasteful number, since it uses less digits than its factorization.

642635136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174 (or 159 counting only the distinct ones).

The product of its digits is 77760, while the sum is 36.

The square root of 642635136 is about 25350.2492295441. The cubic root of 642635136 is about 862.9550123417.

The spelling of 642635136 in words is "six hundred forty-two million, six hundred thirty-five thousand, one hundred thirty-six".