20135864 has 48 divisors (see below), whose sum is σ = 45362880. Its totient is φ = 8346240.

The previous prime is 20135827. The next prime is 20135867. The reversal of 20135864 is 46853102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20135867) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11324 + ... + 12980.

It is an arithmetic number, because the mean of its divisors is an integer number (945060).

Almost surely, 2^20135864 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 20135864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22681440).

20135864 is an abundant number, since it is smaller than the sum of its proper divisors (25227016).

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

20135864 is a wasteful number, since it uses less digits than its factorization.

20135864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1708 (or 1697 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 20135864 is about 4487.3003019633. The cubic root of 20135864 is about 272.0550277940.

Adding to 20135864 its reverse (46853102), we get a palindrome (66988966).

The spelling of 20135864 in words is "twenty million, one hundred thirty-five thousand, eight hundred sixty-four".