21938726 has 16 divisors (see below), whose sum is σ = 33493824. Its totient is φ = 10775784.

The previous prime is 21938723. The next prime is 21938747. The reversal of 21938726 is 62783912.

It is a self number, because there is not a number n which added to its sum of digits gives 21938726.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21938723) 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 7 ways as a sum of consecutive naturals, for example, 46745 + ... + 47211.

It is an arithmetic number, because the mean of its divisors is an integer number (2093364).

Almost surely, 2^21938726 is an apocalyptic number.

21938726 is a deficient number, since it is larger than the sum of its proper divisors (11555098).

21938726 is a wasteful number, since it uses less digits than its factorization.

21938726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 835.

The product of its digits is 36288, while the sum is 38.

The square root of 21938726 is about 4683.8793750480. The cubic root of 21938726 is about 279.9435515458.

The spelling of 21938726 in words is "twenty-one million, nine hundred thirty-eight thousand, seven hundred twenty-six".