21632021023 has 4 divisors (see below), whose sum is σ = 21632564088. Its totient is φ = 21631477960.

The previous prime is 21632021017. The next prime is 21632021027. The reversal of 21632021023 is 32012023612.

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-21632021023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21632020985 and 21632021003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21632021027) 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, 206608 + ... + 293173.

It is an arithmetic number, because the mean of its divisors is an integer number (5408141022).

Almost surely, 2^21632021023 is an apocalyptic number.

21632021023 is a deficient number, since it is larger than the sum of its proper divisors (543065).

21632021023 is an equidigital number, since it uses as much as digits as its factorization.

21632021023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543064.

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 21632021023 its reverse (32012023612), we get a palindrome (53644044635).

The spelling of 21632021023 in words is "twenty-one billion, six hundred thirty-two million, twenty-one thousand, twenty-three".