21727072 has 12 divisors (see below), whose sum is σ = 42775236. Its totient is φ = 10863520.

The previous prime is 21727009. The next prime is 21727081. The reversal of 21727072 is 27072712.

It is a self number, because there is not a number n which added to its sum of digits gives 21727072.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 339454 + ... + 339517.

It is an arithmetic number, because the mean of its divisors is an integer number (3564603).

Almost surely, 2^21727072 is an apocalyptic number.

It is an amenable number.

21727072 is a deficient number, since it is larger than the sum of its proper divisors (21048164).

21727072 is an equidigital number, since it uses as much as digits as its factorization.

21727072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 678981 (or 678973 counting only the distinct ones).

The product of its (nonzero) digits is 2744, while the sum is 28.

The square root of 21727072 is about 4661.2307387642. The cubic root of 21727072 is about 279.0403884611.

Adding to 21727072 its reverse (27072712), we get a palindrome (48799784).

The spelling of 21727072 in words is "twenty-one million, seven hundred twenty-seven thousand, seventy-two".