21943607 has 4 divisors (see below), whose sum is σ = 25078416. Its totient is φ = 18808800.

The previous prime is 21943589. The next prime is 21943609. The reversal of 21943607 is 70634912.

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 21943607 - 2⁶ = 21943543 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 (21943609) 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, 1567394 + ... + 1567407.

It is an arithmetic number, because the mean of its divisors is an integer number (6269604).

Almost surely, 2^21943607 is an apocalyptic number.

21943607 is a deficient number, since it is larger than the sum of its proper divisors (3134809).

21943607 is an equidigital number, since it uses as much as digits as its factorization.

21943607 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3134808.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 21943607 is about 4684.4003885236. The cubic root of 21943607 is about 279.9643109274.

The spelling of 21943607 in words is "twenty-one million, nine hundred forty-three thousand, six hundred seven".