21465873 has 36 divisors (see below), whose sum is σ = 36655632. Its totient is φ = 11999520.

The previous prime is 21465863. The next prime is 21465881. The reversal of 21465873 is 37856412.

It is not a de Polignac number, because 21465873 - 2⁵ = 21465841 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21465803) 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 35 ways as a sum of consecutive naturals, for example, 16090 + ... + 17372.

It is an arithmetic number, because the mean of its divisors is an integer number (1018212).

Almost surely, 2^21465873 is an apocalyptic number.

It is an amenable number.

21465873 is a deficient number, since it is larger than the sum of its proper divisors (15189759).

21465873 is a wasteful number, since it uses less digits than its factorization.

21465873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326 (or 1310 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 21465873 is about 4633.1277772149. The cubic root of 21465873 is about 277.9176860658.

The spelling of 21465873 in words is "twenty-one million, four hundred sixty-five thousand, eight hundred seventy-three".