21899347 has 4 divisors (see below), whose sum is σ = 21908880. Its totient is φ = 21889816.

The previous prime is 21899333. The next prime is 21899363. The reversal of 21899347 is 74399812.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21899347 - 2⁷ = 21899219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21899327) 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, 1029 + ... + 6697.

It is an arithmetic number, because the mean of its divisors is an integer number (5477220).

Almost surely, 2^21899347 is an apocalyptic number.

21899347 is a deficient number, since it is larger than the sum of its proper divisors (9533).

21899347 is an equidigital number, since it uses as much as digits as its factorization.

21899347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9532.

The product of its digits is 108864, while the sum is 43.

The square root of 21899347 is about 4679.6738134191. The cubic root of 21899347 is about 279.7759559815.

The spelling of 21899347 in words is "twenty-one million, eight hundred ninety-nine thousand, three hundred forty-seven".