21947353 has 4 divisors (see below), whose sum is σ = 22361508. Its totient is φ = 21533200.

The previous prime is 21947339. The next prime is 21947363. The reversal of 21947353 is 35374912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14040009 + 7907344 = 3747^2 + 2812^2 .

It is a cyclic number.

It is not a de Polignac number, because 21947353 - 2¹³ = 21939161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21947363) 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, 206998 + ... + 207103.

It is an arithmetic number, because the mean of its divisors is an integer number (5590377).

Almost surely, 2^21947353 is an apocalyptic number.

It is an amenable number.

21947353 is a deficient number, since it is larger than the sum of its proper divisors (414155).

21947353 is an equidigital number, since it uses as much as digits as its factorization.

21947353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414154.

The product of its digits is 22680, while the sum is 34.

The square root of 21947353 is about 4684.8002091872. The cubic root of 21947353 is about 279.9802409526.

The spelling of 21947353 in words is "twenty-one million, nine hundred forty-seven thousand, three hundred fifty-three".