21895506 has 12 divisors (see below), whose sum is σ = 47440302. Its totient is φ = 7298496.

The previous prime is 21895501. The next prime is 21895529. The reversal of 21895506 is 60559812.

It is a happy number.

21895506 is a `hidden beast` number, since 21 + 89 + 550 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21706281 + 189225 = 4659^2 + 435^2 .

It is not an unprimeable number, because it can be changed into a prime (21895501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 608191 + ... + 608226.

Almost surely, 2^21895506 is an apocalyptic number.

21895506 is an abundant number, since it is smaller than the sum of its proper divisors (25544796).

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

21895506 is a wasteful number, since it uses less digits than its factorization.

21895506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1216425 (or 1216422 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 21895506 is about 4679.2634035711. The cubic root of 21895506 is about 279.7595980770.

The spelling of 21895506 in words is "twenty-one million, eight hundred ninety-five thousand, five hundred six".