21346543 has 4 divisors (see below), whose sum is σ = 22602240. Its totient is φ = 20090848.

The previous prime is 21346537. The next prime is 21346547. The reversal of 21346543 is 34564312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21346543 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 (21346547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 627823 + ... + 627856.

It is an arithmetic number, because the mean of its divisors is an integer number (5650560).

Almost surely, 2^21346543 is an apocalyptic number.

21346543 is a deficient number, since it is larger than the sum of its proper divisors (1255697).

21346543 is a wasteful number, since it uses less digits than its factorization.

21346543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1255696.

The product of its digits is 8640, while the sum is 28.

The square root of 21346543 is about 4620.2319205858. The cubic root of 21346543 is about 277.4017421248.

The spelling of 21346543 in words is "twenty-one million, three hundred forty-six thousand, five hundred forty-three".