21727663 has 8 divisors (see below), whose sum is σ = 23226336. Its totient is φ = 20275200.

The previous prime is 21727661. The next prime is 21727669. The reversal of 21727663 is 36672712.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21727663 - 2¹ = 21727661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21727661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10578 + ... + 12463.

It is an arithmetic number, because the mean of its divisors is an integer number (2903292).

Almost surely, 2^21727663 is an apocalyptic number.

21727663 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21727663 is a deficient number, since it is larger than the sum of its proper divisors (1498673).

21727663 is a wasteful number, since it uses less digits than its factorization.

21727663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23105.

The product of its digits is 21168, while the sum is 34.

The square root of 21727663 is about 4661.2941336071. The cubic root of 21727663 is about 279.0429185055.

The spelling of 21727663 in words is "twenty-one million, seven hundred twenty-seven thousand, six hundred sixty-three".