21974943 has 8 divisors (see below), whose sum is σ = 29324800. Its totient is φ = 14637528.

The previous prime is 21974941. The next prime is 21974951. The reversal of 21974943 is 34947912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21974943 - 2¹ = 21974941 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 (21974941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2418 + ... + 7056.

It is an arithmetic number, because the mean of its divisors is an integer number (3665600).

Almost surely, 2^21974943 is an apocalyptic number.

21974943 is a deficient number, since it is larger than the sum of its proper divisors (7349857).

21974943 is a wasteful number, since it uses less digits than its factorization.

21974943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6221.

The product of its digits is 54432, while the sum is 39.

The square root of 21974943 is about 4687.7439136540. The cubic root of 21974943 is about 280.0975128050.

It can be divided in two parts, 2197 and 4943, that added together give a triangular number (7140 = T₁₁₉).

The spelling of 21974943 in words is "twenty-one million, nine hundred seventy-four thousand, nine hundred forty-three".