21110023 has 12 divisors (see below), whose sum is σ = 23604840. Its totient is φ = 18859280.

The previous prime is 21109987. The next prime is 21110027. The reversal of 21110023 is 32001112.

It is not a de Polignac number, because 21110023 - 2²¹ = 19012871 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21109991 and 21110009.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5661 + ... + 8617.

It is an arithmetic number, because the mean of its divisors is an integer number (1967070).

Almost surely, 2^21110023 is an apocalyptic number.

21110023 is a deficient number, since it is larger than the sum of its proper divisors (2494817).

21110023 is a wasteful number, since it uses less digits than its factorization.

21110023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3038 (or 3027 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21110023 is about 4594.5645060223. The cubic root of 21110023 is about 276.3733962763.

Adding to 21110023 its reverse (32001112), we get a palindrome (53111135).

The spelling of 21110023 in words is "twenty-one million, one hundred ten thousand, twenty-three".