21752023 has 12 divisors (see below), whose sum is σ = 22840840. Its totient is φ = 20703312.

The previous prime is 21752021. The next prime is 21752039. The reversal of 21752023 is 32025712.

It is not a de Polignac number, because 21752023 - 2¹ = 21752021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21751985 and 21752003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21752021) 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, 94873 + ... + 95101.

Almost surely, 2^21752023 is an apocalyptic number.

21752023 is a deficient number, since it is larger than the sum of its proper divisors (1088817).

21752023 is an equidigital number, since it uses as much as digits as its factorization.

21752023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366 (or 319 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 21752023 is about 4663.9064098672. The cubic root of 21752023 is about 279.1471626779.

Adding to 21752023 its reverse (32025712), we get a palindrome (53777735).

The spelling of 21752023 in words is "twenty-one million, seven hundred fifty-two thousand, twenty-three".