21102043 has 4 divisors (see below), whose sum is σ = 21118240. Its totient is φ = 21085848.

The previous prime is 21102023. The next prime is 21102047. The reversal of 21102043 is 34020112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21102043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21102047) 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, 5955 + ... + 8812.

It is an arithmetic number, because the mean of its divisors is an integer number (5279560).

Almost surely, 2^21102043 is an apocalyptic number.

21102043 is a deficient number, since it is larger than the sum of its proper divisors (16197).

21102043 is a wasteful number, since it uses less digits than its factorization.

21102043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16196.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21102043 is about 4593.6960064854. The cubic root of 21102043 is about 276.3385670443.

Adding to 21102043 its reverse (34020112), we get a palindrome (55122155).

The spelling of 21102043 in words is "twenty-one million, one hundred two thousand, forty-three".