21455043 has 8 divisors (see below), whose sum is σ = 28643328. Its totient is φ = 14285064.

The previous prime is 21455039. The next prime is 21455051. The reversal of 21455043 is 34055412.

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

It is not a de Polignac number, because 21455043 - 2² = 21455039 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21455023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1555 + ... + 6732.

It is an arithmetic number, because the mean of its divisors is an integer number (3580416).

Almost surely, 2^21455043 is an apocalyptic number.

21455043 is a deficient number, since it is larger than the sum of its proper divisors (7188285).

21455043 is an equidigital number, since it uses as much as digits as its factorization.

21455043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9153.

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 21455043 is about 4631.9588728744. The cubic root of 21455043 is about 277.8709396968.

The spelling of 21455043 in words is "twenty-one million, four hundred fifty-five thousand, forty-three".