21436743 has 8 divisors (see below), whose sum is σ = 28619248. Its totient is φ = 14272704.

The previous prime is 21436721. The next prime is 21436757. The reversal of 21436743 is 34763412.

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

It is not a de Polignac number, because 21436743 - 2¹⁰ = 21435719 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21436743.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21436763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1630 + ... + 6747.

It is an arithmetic number, because the mean of its divisors is an integer number (3577406).

Almost surely, 2^21436743 is an apocalyptic number.

21436743 is a deficient number, since it is larger than the sum of its proper divisors (7182505).

21436743 is an equidigital number, since it uses as much as digits as its factorization.

21436743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9233.

The product of its digits is 12096, while the sum is 30.

The square root of 21436743 is about 4629.9830453253. The cubic root of 21436743 is about 277.7919142258.

The spelling of 21436743 in words is "twenty-one million, four hundred thirty-six thousand, seven hundred forty-three".