21250726 has 16 divisors (see below), whose sum is σ = 36944640. Its totient is φ = 8978760.

The previous prime is 21250709. The next prime is 21250771. The reversal of 21250726 is 62705212.

It is a self number, because there is not a number n which added to its sum of digits gives 21250726.

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, 9696 + ... + 11683.

It is an arithmetic number, because the mean of its divisors is an integer number (2309040).

Almost surely, 2^21250726 is an apocalyptic number.

21250726 is a deficient number, since it is larger than the sum of its proper divisors (15693914).

21250726 is a wasteful number, since it uses less digits than its factorization.

21250726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21459.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 21250726 is about 4609.8509737301. The cubic root of 21250726 is about 276.9860671484.

Adding to 21250726 its reverse (62705212), we get a palindrome (83955938).

The spelling of 21250726 in words is "twenty-one million, two hundred fifty thousand, seven hundred twenty-six".