21905950 has 24 divisors (see below), whose sum is σ = 44450280. Its totient is φ = 7965600.

The previous prime is 21905929. The next prime is 21905953. The reversal of 21905950 is 5950912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21905953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19365 + ... + 20464.

It is an arithmetic number, because the mean of its divisors is an integer number (1852095).

Almost surely, 2^21905950 is an apocalyptic number.

21905950 is an abundant number, since it is smaller than the sum of its proper divisors (22544330).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21905950 is a wasteful number, since it uses less digits than its factorization.

21905950 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39852 (or 39847 counting only the distinct ones).

The product of its (nonzero) digits is 4050, while the sum is 31.

The square root of 21905950 is about 4680.3792581371. The cubic root of 21905950 is about 279.8040721166.

The spelling of 21905950 in words is "twenty-one million, nine hundred five thousand, nine hundred fifty".