21974339 has 4 divisors (see below), whose sum is σ = 21983856. Its totient is φ = 21964824.

The previous prime is 21974321. The next prime is 21974357. The reversal of 21974339 is 93347912.

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 an interprime number because it is at equal distance from previous prime (21974321) and next prime (21974357).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21974339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21974369) 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, 1157 + ... + 6729.

It is an arithmetic number, because the mean of its divisors is an integer number (5495964).

Almost surely, 2^21974339 is an apocalyptic number.

21974339 is a deficient number, since it is larger than the sum of its proper divisors (9517).

21974339 is an equidigital number, since it uses as much as digits as its factorization.

21974339 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9516.

The product of its digits is 40824, while the sum is 38.

The square root of 21974339 is about 4687.6794898969. The cubic root of 21974339 is about 280.0949465420.

The spelling of 21974339 in words is "twenty-one million, nine hundred seventy-four thousand, three hundred thirty-nine".