21850899 has 32 divisors (see below), whose sum is σ = 35675136. Its totient is φ = 11612160.

The previous prime is 21850883. The next prime is 21850901. The reversal of 21850899 is 99805812.

It is a happy number.

It is not a de Polignac number, because 21850899 - 2⁴ = 21850883 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21850899.

It is not an unprimeable number, because it can be changed into a prime (21850819) 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 in 31 ways as a sum of consecutive naturals, for example, 34314 + ... + 34944.

It is an arithmetic number, because the mean of its divisors is an integer number (1114848).

Almost surely, 2^21850899 is an apocalyptic number.

21850899 is a deficient number, since it is larger than the sum of its proper divisors (13824237).

21850899 is a wasteful number, since it uses less digits than its factorization.

21850899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 755.

The product of its (nonzero) digits is 51840, while the sum is 42.

The square root of 21850899 is about 4674.4945181271. The cubic root of 21850899 is about 279.5694872157.

The spelling of 21850899 in words is "twenty-one million, eight hundred fifty thousand, eight hundred ninety-nine".