21346723 has 4 divisors (see below), whose sum is σ = 21455280. Its totient is φ = 21238168.

The previous prime is 21346711. The next prime is 21346751. The reversal of 21346723 is 32764312.

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 21346723 - 2⁹ = 21346211 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21346691 and 21346700.

It is not an unprimeable number, because it can be changed into a prime (21346753) 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 3 ways as a sum of consecutive naturals, for example, 53983 + ... + 54376.

It is an arithmetic number, because the mean of its divisors is an integer number (5363820).

Almost surely, 2^21346723 is an apocalyptic number.

21346723 is a deficient number, since it is larger than the sum of its proper divisors (108557).

21346723 is a wasteful number, since it uses less digits than its factorization.

21346723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108556.

The product of its digits is 6048, while the sum is 28.

The square root of 21346723 is about 4620.2514000864. The cubic root of 21346723 is about 277.4025218322.

The spelling of 21346723 in words is "twenty-one million, three hundred forty-six thousand, seven hundred twenty-three".