21002352023 has 4 divisors (see below), whose sum is σ = 21030619728. Its totient is φ = 20974084320.

The previous prime is 21002351977. The next prime is 21002352079. The reversal of 21002352023 is 32025320012.

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

It is a cyclic number.

It is not a de Polignac number, because 21002352023 - 2¹⁸ = 21002089879 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002351986 and 21002352004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002352923) 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, 14132738 + ... + 14134223.

It is an arithmetic number, because the mean of its divisors is an integer number (5257654932).

Almost surely, 2^21002352023 is an apocalyptic number.

21002352023 is a deficient number, since it is larger than the sum of its proper divisors (28267705).

21002352023 is an equidigital number, since it uses as much as digits as its factorization.

21002352023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28267704.

The product of its (nonzero) digits is 720, while the sum is 20.

Adding to 21002352023 its reverse (32025320012), we get a palindrome (53027672035).

The spelling of 21002352023 in words is "twenty-one billion, two million, three hundred fifty-two thousand, twenty-three".