21132623 has 2 divisors, whose sum is σ = 21132624. Its totient is φ = 21132622.

The previous prime is 21132611. The next prime is 21132659. The reversal of 21132623 is 32623112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21132623 - 2¹⁶ = 21067087 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21132595 and 21132604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21102623) 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 as a sum of consecutive naturals, namely, 10566311 + 10566312.

It is an arithmetic number, because the mean of its divisors is an integer number (10566312).

Almost surely, 2^21132623 is an apocalyptic number.

21132623 is a deficient number, since it is larger than the sum of its proper divisors (1).

21132623 is an equidigital number, since it uses as much as digits as its factorization.

21132623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 20.

The square root of 21132623 is about 4597.0232759907. The cubic root of 21132623 is about 276.4719878492.

Adding to 21132623 its reverse (32623112), we get a palindrome (53755735).

The spelling of 21132623 in words is "twenty-one million, one hundred thirty-two thousand, six hundred twenty-three".