21636479 has 8 divisors (see below), whose sum is σ = 22226400. Its totient is φ = 21049600.

The previous prime is 21636473. The next prime is 21636487. The reversal of 21636479 is 97463612.

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 21636479 - 2⁴ = 21636463 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 (21636473) 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, 24119 + ... + 24999.

It is an arithmetic number, because the mean of its divisors is an integer number (2778300).

Almost surely, 2^21636479 is an apocalyptic number.

21636479 is a deficient number, since it is larger than the sum of its proper divisors (589921).

21636479 is an equidigital number, since it uses as much as digits as its factorization.

21636479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1521.

The product of its digits is 54432, while the sum is 38.

The square root of 21636479 is about 4651.5028754156. The cubic root of 21636479 is about 278.6520200999.

The spelling of 21636479 in words is "twenty-one million, six hundred thirty-six thousand, four hundred seventy-nine".