21514663 has 4 divisors (see below), whose sum is σ = 22015048. Its totient is φ = 21014280.

The previous prime is 21514657. The next prime is 21514667. The reversal of 21514663 is 36641512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21514663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21514667) 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, 250128 + ... + 250213.

It is an arithmetic number, because the mean of its divisors is an integer number (5503762).

Almost surely, 2^21514663 is an apocalyptic number.

21514663 is a deficient number, since it is larger than the sum of its proper divisors (500385).

21514663 is an equidigital number, since it uses as much as digits as its factorization.

21514663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500384.

The product of its digits is 4320, while the sum is 28.

The square root of 21514663 is about 4638.3901302068. The cubic root of 21514663 is about 278.1280873789.

It can be divided in two parts, 215 and 14663, that added together give a triangular number (14878 = T₁₇₂).

The spelling of 21514663 in words is "twenty-one million, five hundred fourteen thousand, six hundred sixty-three".