21056043 has 8 divisors (see below), whose sum is σ = 28182528. Its totient is φ = 13983464.

The previous prime is 21056039. The next prime is 21056051. The reversal of 21056043 is 34065012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21056043 - 2² = 21056039 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21056033) 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, 12555 + ... + 14132.

It is an arithmetic number, because the mean of its divisors is an integer number (3522816).

Almost surely, 2^21056043 is an apocalyptic number.

21056043 is a deficient number, since it is larger than the sum of its proper divisors (7126485).

21056043 is a wasteful number, since it uses less digits than its factorization.

21056043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26953.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 21056043 is about 4588.6864133431. The cubic root of 21056043 is about 276.1376256494.

The spelling of 21056043 in words is "twenty-one million, fifty-six thousand, forty-three".