21736943 has 8 divisors (see below), whose sum is σ = 22359888. Its totient is φ = 21121984.

The previous prime is 21736937. The next prime is 21736963. The reversal of 21736943 is 34963712.

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

It is not a de Polignac number, because 21736943 - 2⁶ = 21736879 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 (21736933) 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, 3755 + ... + 7587.

It is an arithmetic number, because the mean of its divisors is an integer number (2794986).

Almost surely, 2^21736943 is an apocalyptic number.

21736943 is a deficient number, since it is larger than the sum of its proper divisors (622945).

21736943 is a wasteful number, since it uses less digits than its factorization.

21736943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3993.

The product of its digits is 27216, while the sum is 35.

The square root of 21736943 is about 4662.2894590534. The cubic root of 21736943 is about 279.0826397541.

The spelling of 21736943 in words is "twenty-one million, seven hundred thirty-six thousand, nine hundred forty-three".