21861323 has 8 divisors (see below), whose sum is σ = 24430896. Its totient is φ = 19388800.

The previous prime is 21861313. The next prime is 21861341. The reversal of 21861323 is 32316812.

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 21861323 - 2⁸ = 21861067 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21861292 and 21861301.

It is not an unprimeable number, because it can be changed into a prime (21861313) 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, 23786 + ... + 24687.

It is an arithmetic number, because the mean of its divisors is an integer number (3053862).

Almost surely, 2^21861323 is an apocalyptic number.

21861323 is a deficient number, since it is larger than the sum of its proper divisors (2569573).

21861323 is a wasteful number, since it uses less digits than its factorization.

21861323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48525.

The product of its digits is 1728, while the sum is 26.

The square root of 21861323 is about 4675.6093720498. The cubic root of 21861323 is about 279.6139364783.

The spelling of 21861323 in words is "twenty-one million, eight hundred sixty-one thousand, three hundred twenty-three".