21282623 has 4 divisors (see below), whose sum is σ = 22534560. Its totient is φ = 20030688.

The previous prime is 21282601. The next prime is 21282629. The reversal of 21282623 is 32628212.

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 21282623 - 2⁶ = 21282559 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21282592 and 21282601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21282629) 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, 625943 + ... + 625976.

It is an arithmetic number, because the mean of its divisors is an integer number (5633640).

Almost surely, 2^21282623 is an apocalyptic number.

21282623 is a deficient number, since it is larger than the sum of its proper divisors (1251937).

21282623 is a wasteful number, since it uses less digits than its factorization.

21282623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1251936.

The product of its digits is 2304, while the sum is 26.

The square root of 21282623 is about 4613.3093327892. The cubic root of 21282623 is about 277.1245817550.

The spelling of 21282623 in words is "twenty-one million, two hundred eighty-two thousand, six hundred twenty-three".