21249726 has 16 divisors (see below), whose sum is σ = 43536528. Its totient is φ = 6910400.

The previous prime is 21249719. The next prime is 21249731. The reversal of 21249726 is 62794212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42945 + ... + 43436.

It is an arithmetic number, because the mean of its divisors is an integer number (2721033).

Almost surely, 2^21249726 is an apocalyptic number.

21249726 is an abundant number, since it is smaller than the sum of its proper divisors (22286802).

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

21249726 is a wasteful number, since it uses less digits than its factorization.

21249726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86427.

The product of its digits is 12096, while the sum is 33.

The square root of 21249726 is about 4609.7425090779. The cubic root of 21249726 is about 276.9817223492.

The spelling of 21249726 in words is "twenty-one million, two hundred forty-nine thousand, seven hundred twenty-six".