21272646 has 16 divisors (see below), whose sum is σ = 43084800. Its totient is φ = 7000968.

The previous prime is 21272621. The next prime is 21272681. The reversal of 21272646 is 64627212.

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, 21966 + ... + 22913.

It is an arithmetic number, because the mean of its divisors is an integer number (2692800).

Almost surely, 2^21272646 is an apocalyptic number.

21272646 is an abundant number, since it is smaller than the sum of its proper divisors (21812154).

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

21272646 is a wasteful number, since it uses less digits than its factorization.

21272646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44963.

The product of its digits is 8064, while the sum is 30.

The square root of 21272646 is about 4612.2278781517. The cubic root of 21272646 is about 277.0812709264.

Adding to 21272646 its reverse (64627212), we get a palindrome (85899858).

The spelling of 21272646 in words is "twenty-one million, two hundred seventy-two thousand, six hundred forty-six".