21612463 has 4 divisors (see below), whose sum is σ = 21750280. Its totient is φ = 21474648.

The previous prime is 21612431. The next prime is 21612497. The reversal of 21612463 is 36421612.

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

It is a cyclic number.

It is not a de Polignac number, because 21612463 - 2⁵ = 21612431 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 (21612413) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68673 + ... + 68986.

It is an arithmetic number, because the mean of its divisors is an integer number (5437570).

Almost surely, 2^21612463 is an apocalyptic number.

21612463 is a deficient number, since it is larger than the sum of its proper divisors (137817).

21612463 is a wasteful number, since it uses less digits than its factorization.

21612463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137816.

The product of its digits is 1728, while the sum is 25.

The square root of 21612463 is about 4648.9206274145. The cubic root of 21612463 is about 278.5488827939.

It can be divided in two parts, 2161 and 2463, that added together give a square (4624 = 68²).

The spelling of 21612463 in words is "twenty-one million, six hundred twelve thousand, four hundred sixty-three".