21289926 has 16 divisors (see below), whose sum is σ = 48662784. Its totient is φ = 6082824.

The previous prime is 21289913. The next prime is 21289949. The reversal of 21289926 is 62998212.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 253410 + ... + 253493.

It is an arithmetic number, because the mean of its divisors is an integer number (3041424).

Almost surely, 2^21289926 is an apocalyptic number.

21289926 is an abundant number, since it is smaller than the sum of its proper divisors (27372858).

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

21289926 is a wasteful number, since it uses less digits than its factorization.

21289926 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506915.

The product of its digits is 31104, while the sum is 39.

The square root of 21289926 is about 4614.1007791335. The cubic root of 21289926 is about 277.1562759902.

The spelling of 21289926 in words is "twenty-one million, two hundred eighty-nine thousand, nine hundred twenty-six".