21136312 has 8 divisors (see below), whose sum is σ = 39630600. Its totient is φ = 10568152.

The previous prime is 21136277. The next prime is 21136319. The reversal of 21136312 is 21363112.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×21136312² = 893487369922688, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21136312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21136319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321012 + ... + 1321027.

It is an arithmetic number, because the mean of its divisors is an integer number (4953825).

Almost surely, 2^21136312 is an apocalyptic number.

It is an amenable number.

21136312 is a deficient number, since it is larger than the sum of its proper divisors (18494288).

21136312 is a wasteful number, since it uses less digits than its factorization.

21136312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2642045 (or 2642041 counting only the distinct ones).

The product of its digits is 216, while the sum is 19.

The square root of 21136312 is about 4597.4244963893. The cubic root of 21136312 is about 276.4880742861.

Adding to 21136312 its reverse (21363112), we get a palindrome (42499424).

The spelling of 21136312 in words is "twenty-one million, one hundred thirty-six thousand, three hundred twelve".