21850918 has 4 divisors (see below), whose sum is σ = 32776380. Its totient is φ = 10925458.

The previous prime is 21850901. The next prime is 21850919. The reversal of 21850918 is 81905812.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21850919) by changing a digit.

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 as a sum of consecutive naturals, namely, 5462728 + ... + 5462731.

It is an arithmetic number, because the mean of its divisors is an integer number (8194095).

Almost surely, 2^21850918 is an apocalyptic number.

21850918 is a deficient number, since it is larger than the sum of its proper divisors (10925462).

21850918 is a wasteful number, since it uses less digits than its factorization.

21850918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10925461.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 21850918 is about 4674.4965504319. The cubic root of 21850918 is about 279.5695682470.

The spelling of 21850918 in words is "twenty-one million, eight hundred fifty thousand, nine hundred eighteen".