21488663 has 16 divisors (see below), whose sum is σ = 26127360. Its totient is φ = 17252736.

The previous prime is 21488651. The next prime is 21488671. The reversal of 21488663 is 36688412.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21488663 - 2¹⁸ = 21226519 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21488603) 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 15 ways as a sum of consecutive naturals, for example, 42470 + ... + 42972.

It is an arithmetic number, because the mean of its divisors is an integer number (1632960).

Almost surely, 2^21488663 is an apocalyptic number.

21488663 is a deficient number, since it is larger than the sum of its proper divisors (4638697).

21488663 is a wasteful number, since it uses less digits than its factorization.

21488663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886.

The product of its digits is 55296, while the sum is 38.

The square root of 21488663 is about 4635.5865863987. The cubic root of 21488663 is about 278.0160049789.

The spelling of 21488663 in words is "twenty-one million, four hundred eighty-eight thousand, six hundred sixty-three".