21943307 has 4 divisors (see below), whose sum is σ = 22035360. Its totient is φ = 21851256.

The previous prime is 21943303. The next prime is 21943321. The reversal of 21943307 is 70334912.

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 21943307 - 2² = 21943303 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21943307.

It is not an unprimeable number, because it can be changed into a prime (21943301) 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, 45668 + ... + 46145.

It is an arithmetic number, because the mean of its divisors is an integer number (5508840).

Almost surely, 2^21943307 is an apocalyptic number.

21943307 is a deficient number, since it is larger than the sum of its proper divisors (92053).

21943307 is an equidigital number, since it uses as much as digits as its factorization.

21943307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92052.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 21943307 is about 4684.3683672401. The cubic root of 21943307 is about 279.9630350862.

The spelling of 21943307 in words is "twenty-one million, nine hundred forty-three thousand, three hundred seven".