21135996 has 36 divisors (see below), whose sum is σ = 61060272. Its totient is φ = 6038784.

The previous prime is 21135971. The next prime is 21135997. The reversal of 21135996 is 69953112.

21135996 is a `hidden beast` number, since 211 + 359 + 96 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

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 21135996.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21135997) 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, 41685 + ... + 42188.

Almost surely, 2^21135996 is an apocalyptic number.

It is an amenable number.

21135996 is an abundant number, since it is smaller than the sum of its proper divisors (39924276).

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

21135996 is a wasteful number, since it uses less digits than its factorization.

21135996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83890 (or 83885 counting only the distinct ones).

The product of its digits is 14580, while the sum is 36.

The square root of 21135996 is about 4597.3901291929. The cubic root of 21135996 is about 276.4866963941.

The spelling of 21135996 in words is "twenty-one million, one hundred thirty-five thousand, nine hundred ninety-six".