21923623 has 8 divisors (see below), whose sum is σ = 23666400. Its totient is φ = 20246688.

The previous prime is 21923621. The next prime is 21923639. The reversal of 21923623 is 32632912.

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 21923623 - 2¹ = 21923621 is a prime.

It is a super-2 number, since 2×21923623² = 961290490892258, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21923591 and 21923600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21923621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15768 + ... + 17101.

It is an arithmetic number, because the mean of its divisors is an integer number (2958300).

Almost surely, 2^21923623 is an apocalyptic number.

21923623 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21923623 is a deficient number, since it is larger than the sum of its proper divisors (1742777).

21923623 is a wasteful number, since it uses less digits than its factorization.

21923623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32921.

The product of its digits is 3888, while the sum is 28.

The square root of 21923623 is about 4682.2668655257. The cubic root of 21923623 is about 279.8792974648.

The spelling of 21923623 in words is "twenty-one million, nine hundred twenty-three thousand, six hundred twenty-three".