21909834 has 12 divisors (see below), whose sum is σ = 47471346. Its totient is φ = 7303272.

The previous prime is 21909817. The next prime is 21909857. The reversal of 21909834 is 43890912.

It can be written as a sum of positive squares in only one way, i.e., 12006225 + 9903609 = 3465^2 + 3147^2 .

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 608589 + ... + 608624.

Almost surely, 2^21909834 is an apocalyptic number.

21909834 is an abundant number, since it is smaller than the sum of its proper divisors (25561512).

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

21909834 is a wasteful number, since it uses less digits than its factorization.

21909834 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217221 (or 1217218 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 21909834 is about 4680.7941633872. The cubic root of 21909834 is about 279.8206078796.

The spelling of 21909834 in words is "twenty-one million, nine hundred nine thousand, eight hundred thirty-four".