21727472 has 20 divisors (see below), whose sum is σ = 45335640. Its totient is φ = 10027968.

The previous prime is 21727463. The next prime is 21727477. The reversal of 21727472 is 27472712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21727477) 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 3 ways as a sum of consecutive naturals, for example, 52022 + ... + 52437.

It is an arithmetic number, because the mean of its divisors is an integer number (2266782).

Almost surely, 2^21727472 is an apocalyptic number.

It is an amenable number.

21727472 is an abundant number, since it is smaller than the sum of its proper divisors (23608168).

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

21727472 is a wasteful number, since it uses less digits than its factorization.

21727472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104480 (or 104474 counting only the distinct ones).

The product of its digits is 10976, while the sum is 32.

The square root of 21727472 is about 4661.2736456896. The cubic root of 21727472 is about 279.0421008481.

The spelling of 21727472 in words is "twenty-one million, seven hundred twenty-seven thousand, four hundred seventy-two".