21134623 has 4 divisors (see below), whose sum is σ = 21296088. Its totient is φ = 20973160.

The previous prime is 21134611. The next prime is 21134657. The reversal of 21134623 is 32643112.

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 21134623 - 2¹³ = 21126431 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21134594 and 21134603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21134123) 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, 80536 + ... + 80797.

It is an arithmetic number, because the mean of its divisors is an integer number (5324022).

Almost surely, 2^21134623 is an apocalyptic number.

21134623 is a deficient number, since it is larger than the sum of its proper divisors (161465).

21134623 is a wasteful number, since it uses less digits than its factorization.

21134623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161464.

The product of its digits is 864, while the sum is 22.

The square root of 21134623 is about 4597.2408029165. The cubic root of 21134623 is about 276.4807093810.

Adding to 21134623 its reverse (32643112), we get a palindrome (53777735).

The spelling of 21134623 in words is "twenty-one million, one hundred thirty-four thousand, six hundred twenty-three".