21728114 has 8 divisors (see below), whose sum is σ = 33387228. Its totient is φ = 10599040.

The previous prime is 21728111. The next prime is 21728129. The reversal of 21728114 is 41182712.

It can be written as a sum of positive squares in 2 ways, for example, as 15642025 + 6086089 = 3955^2 + 2467^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21728114² = 944221875993992, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21728111) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 132407 + ... + 132570.

Almost surely, 2^21728114 is an apocalyptic number.

21728114 is a deficient number, since it is larger than the sum of its proper divisors (11659114).

21728114 is a wasteful number, since it uses less digits than its factorization.

21728114 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265020.

The product of its digits is 896, while the sum is 26.

The square root of 21728114 is about 4661.3425104791. The cubic root of 21728114 is about 279.0448491854.

The spelling of 21728114 in words is "twenty-one million, seven hundred twenty-eight thousand, one hundred fourteen".