21629023 has 4 divisors (see below), whose sum is σ = 23292808. Its totient is φ = 19965240.

The previous prime is 21629021. The next prime is 21629029. The reversal of 21629023 is 32092612.

It is a happy number.

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 21629023 - 2¹ = 21629021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21629021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 831873 + ... + 831898.

It is an arithmetic number, because the mean of its divisors is an integer number (5823202).

Almost surely, 2^21629023 is an apocalyptic number.

21629023 is a deficient number, since it is larger than the sum of its proper divisors (1663785).

21629023 is a wasteful number, since it uses less digits than its factorization.

21629023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663784.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 21629023 is about 4650.7013449586. The cubic root of 21629023 is about 278.6200082962.

The spelling of 21629023 in words is "twenty-one million, six hundred twenty-nine thousand, twenty-three".