21252118 has 8 divisors (see below), whose sum is σ = 32207112. Its totient is φ = 10516416.

The previous prime is 21252113. The next prime is 21252137. The reversal of 21252118 is 81125212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21252113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54580 + ... + 54967.

It is an arithmetic number, because the mean of its divisors is an integer number (4025889).

Almost surely, 2^21252118 is an apocalyptic number.

21252118 is a deficient number, since it is larger than the sum of its proper divisors (10954994).

21252118 is a wasteful number, since it uses less digits than its factorization.

21252118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109646.

The product of its digits is 320, while the sum is 22.

The square root of 21252118 is about 4610.0019522772. The cubic root of 21252118 is about 276.9921148820.

The spelling of 21252118 in words is "twenty-one million, two hundred fifty-two thousand, one hundred eighteen".