21842623 has 8 divisors (see below), whose sum is σ = 23869440. Its totient is φ = 19822680.

The previous prime is 21842593. The next prime is 21842651. The reversal of 21842623 is 32624812.

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 21842623 - 2⁵ = 21842591 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21842591 and 21842600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21842683) 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, 6786 + ... + 9472.

It is an arithmetic number, because the mean of its divisors is an integer number (2983680).

Almost surely, 2^21842623 is an apocalyptic number.

21842623 is a deficient number, since it is larger than the sum of its proper divisors (2026817).

21842623 is a wasteful number, since it uses less digits than its factorization.

21842623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3437.

The product of its digits is 4608, while the sum is 28.

The square root of 21842623 is about 4673.6092048865. The cubic root of 21842623 is about 279.5341872304.

The spelling of 21842623 in words is "twenty-one million, eight hundred forty-two thousand, six hundred twenty-three".