21125995 has 12 divisors (see below), whose sum is σ = 27866160. Its totient is φ = 15363920.

The previous prime is 21125989. The next prime is 21126013. The reversal of 21125995 is 59952112.

It is a de Polignac number, because none of the positive numbers 2^k-21125995 is a prime.

It is a super-3 number, since 3×21125995³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21125995.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16855 + ... + 18064.

It is an arithmetic number, because the mean of its divisors is an integer number (2322180).

Almost surely, 2^21125995 is an apocalyptic number.

21125995 is a deficient number, since it is larger than the sum of its proper divisors (6740165).

21125995 is a wasteful number, since it uses less digits than its factorization.

21125995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34946 (or 34935 counting only the distinct ones).

The product of its digits is 8100, while the sum is 34.

The square root of 21125995 is about 4596.3023181684. The cubic root of 21125995 is about 276.4430807586.

The spelling of 21125995 in words is "twenty-one million, one hundred twenty-five thousand, nine hundred ninety-five".