21995136 has 96 divisors (see below), whose sum is σ = 64536420. Its totient is φ = 7188480.

The previous prime is 21995123. The next prime is 21995143. The reversal of 21995136 is 63159912.

It can be written as a sum of positive squares in 2 ways, for example, as 13838400 + 8156736 = 3720^2 + 2856^2 .

It is a tau number, because it is divible by the number of its divisors (96).

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 21995136.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70116 + ... + 70428.

Almost surely, 2^21995136 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 21995136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32268210).

21995136 is an abundant number, since it is smaller than the sum of its proper divisors (42541284).

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

21995136 is a wasteful number, since it uses less digits than its factorization.

21995136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394 (or 379 counting only the distinct ones).

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

The square root of 21995136 is about 4689.8972270189. The cubic root of 21995136 is about 280.1832813627.

The spelling of 21995136 in words is "twenty-one million, nine hundred ninety-five thousand, one hundred thirty-six".