21136512 has 64 divisors (see below), whose sum is σ = 59119200. Its totient is φ = 6672384.

The previous prime is 21136501. The next prime is 21136519. The reversal of 21136512 is 21563112.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×21136512² = 893504279052288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21136519) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5848 + ... + 8744.

Almost surely, 2^21136512 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 21136512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29559600).

21136512 is an abundant number, since it is smaller than the sum of its proper divisors (37982688).

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

21136512 is a wasteful number, since it uses less digits than its factorization.

21136512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2933 (or 2921 counting only the distinct ones).

The product of its digits is 360, while the sum is 21.

The square root of 21136512 is about 4597.4462476466. The cubic root of 21136512 is about 276.4889463626.

Adding to 21136512 its reverse (21563112), we get a palindrome (42699624).

The spelling of 21136512 in words is "twenty-one million, one hundred thirty-six thousand, five hundred twelve".