21101043 has 4 divisors (see below), whose sum is σ = 28134728. Its totient is φ = 14067360.

The previous prime is 21101033. The next prime is 21101123. The reversal of 21101043 is 34010112.

It is a happy number.

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

It is not a de Polignac number, because 21101043 - 2⁴ = 21101027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101033) 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, 3516838 + ... + 3516843.

It is an arithmetic number, because the mean of its divisors is an integer number (7033682).

Almost surely, 2^21101043 is an apocalyptic number.

21101043 is a deficient number, since it is larger than the sum of its proper divisors (7033685).

21101043 is an equidigital number, since it uses as much as digits as its factorization.

21101043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7033684.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21101043 is about 4593.5871603791. The cubic root of 21101043 is about 276.3342018598.

Adding to 21101043 its reverse (34010112), we get a palindrome (55111155).

The spelling of 21101043 in words is "twenty-one million, one hundred one thousand, forty-three".