21900344 has 8 divisors (see below), whose sum is σ = 41063160. Its totient is φ = 10950168.

The previous prime is 21900343. The next prime is 21900349. The reversal of 21900344 is 44300912.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21900341) 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 as a sum of consecutive naturals, namely, 1368764 + ... + 1368779.

It is an arithmetic number, because the mean of its divisors is an integer number (5132895).

Almost surely, 2^21900344 is an apocalyptic number.

It is an amenable number.

21900344 is a deficient number, since it is larger than the sum of its proper divisors (19162816).

21900344 is a wasteful number, since it uses less digits than its factorization.

21900344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2737549 (or 2737545 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21900344 is about 4679.7803367252. The cubic root of 21900344 is about 279.7802016544.

The spelling of 21900344 in words is "twenty-one million, nine hundred thousand, three hundred forty-four".