21437043 has 4 divisors (see below), whose sum is σ = 28582728. Its totient is φ = 14291360.

The previous prime is 21437041. The next prime is 21437063. The reversal of 21437043 is 34073412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21437043 - 2¹ = 21437041 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21437041) 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, 3572838 + ... + 3572843.

It is an arithmetic number, because the mean of its divisors is an integer number (7145682).

Almost surely, 2^21437043 is an apocalyptic number.

21437043 is a deficient number, since it is larger than the sum of its proper divisors (7145685).

21437043 is an equidigital number, since it uses as much as digits as its factorization.

21437043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7145684.

The product of its (nonzero) digits is 2016, while the sum is 24.

The square root of 21437043 is about 4630.0154427388. The cubic root of 21437043 is about 277.7932100878.

The spelling of 21437043 in words is "twenty-one million, four hundred thirty-seven thousand, forty-three".