21256895 has 8 divisors (see below), whose sum is σ = 27827280. Its totient is φ = 15459520.

The previous prime is 21256867. The next prime is 21256909. The reversal of 21256895 is 59865212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21256895 - 2¹² = 21252799 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 193190 + ... + 193299.

It is an arithmetic number, because the mean of its divisors is an integer number (3478410).

Almost surely, 2^21256895 is an apocalyptic number.

21256895 is a deficient number, since it is larger than the sum of its proper divisors (6570385).

21256895 is a wasteful number, since it uses less digits than its factorization.

21256895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386505.

The product of its digits is 43200, while the sum is 38.

The square root of 21256895 is about 4610.5200357443. The cubic root of 21256895 is about 277.0128672011.

The spelling of 21256895 in words is "twenty-one million, two hundred fifty-six thousand, eight hundred ninety-five".