21273726 has 16 divisors (see below), whose sum is σ = 42656400. Its totient is φ = 7073088.

The previous prime is 21273713. The next prime is 21273737. The reversal of 21273726 is 62737212.

It is a junction number, because it is equal to n+sod(n) for n = 21273693 and 21273702.

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, 1881 + ... + 6788.

It is an arithmetic number, because the mean of its divisors is an integer number (2666025).

Almost surely, 2^21273726 is an apocalyptic number.

21273726 is an abundant number, since it is smaller than the sum of its proper divisors (21382674).

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

21273726 is a wasteful number, since it uses less digits than its factorization.

21273726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9083.

The product of its digits is 7056, while the sum is 30.

The square root of 21273726 is about 4612.3449567438. The cubic root of 21273726 is about 277.0859599326.

It can be divided in two parts, 2 and 1273726, that multiplied together give a palindrome (2547452).

The spelling of 21273726 in words is "twenty-one million, two hundred seventy-three thousand, seven hundred twenty-six".