21343943 has 2 divisors, whose sum is σ = 21343944. Its totient is φ = 21343942.

The previous prime is 21343939. The next prime is 21343951. The reversal of 21343943 is 34934312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21343943 - 2² = 21343939 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21343243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10671971 + 10671972.

It is an arithmetic number, because the mean of its divisors is an integer number (10671972).

Almost surely, 2^21343943 is an apocalyptic number.

21343943 is a deficient number, since it is larger than the sum of its proper divisors (1).

21343943 is an equidigital number, since it uses as much as digits as its factorization.

21343943 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 29.

The square root of 21343943 is about 4619.9505408608. The cubic root of 21343943 is about 277.3904791955.

The spelling of 21343943 in words is "twenty-one million, three hundred forty-three thousand, nine hundred forty-three".