23100021 has 30 divisors (see below), whose sum is σ = 38961910. Its totient is φ = 13187664.

The previous prime is 23100017. The next prime is 23100031. The reversal of 23100021 is 12000132.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19448100 + 3651921 = 4410^2 + 1911^2 .

It is not a de Polignac number, because 23100021 - 2² = 23100017 is a prime.

It is a super-2 number, since 2×23100021² = 1067221940400882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 23099976 and 23100012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23100001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 21075 + ... + 22143.

Almost surely, 2^23100021 is an apocalyptic number.

23100021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

23100021 is a deficient number, since it is larger than the sum of its proper divisors (15861889).

23100021 is an equidigital number, since it uses as much as digits as its factorization.

23100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1103 (or 1079 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 23100021 is about 4806.2481209359. The cubic root of 23100021 is about 284.7983430355.

Adding to 23100021 its reverse (12000132), we get a palindrome (35100153).

The spelling of 23100021 in words is "twenty-three million, one hundred thousand, twenty-one".