21054043 has 4 divisors (see below), whose sum is σ = 21092400. Its totient is φ = 21015688.

The previous prime is 21054037. The next prime is 21054049. The reversal of 21054043 is 34045012.

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

It is an interprime number because it is at equal distance from previous prime (21054037) and next prime (21054049).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21054043 is a prime.

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 21054043.

It is not an unprimeable number, because it can be changed into a prime (21054049) 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, 18343 + ... + 19456.

It is an arithmetic number, because the mean of its divisors is an integer number (5273100).

Almost surely, 2^21054043 is an apocalyptic number.

21054043 is a deficient number, since it is larger than the sum of its proper divisors (38357).

21054043 is an equidigital number, since it uses as much as digits as its factorization.

21054043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38356.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21054043 is about 4588.4684808768. The cubic root of 21054043 is about 276.1288824311.

Adding to 21054043 its reverse (34045012), we get a palindrome (55099055).

The spelling of 21054043 in words is "twenty-one million, fifty-four thousand, forty-three".