21201201023 has 4 divisors (see below), whose sum is σ = 21261949800. Its totient is φ = 21140452248.

The previous prime is 21201200987. The next prime is 21201201061. The reversal of 21201201023 is 32010210212.

It is a happy number.

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 21201201023 - 2²⁴ = 21184423807 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21201200989 and 21201201007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201201083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30373865 + ... + 30374562.

It is an arithmetic number, because the mean of its divisors is an integer number (5315487450).

Almost surely, 2^21201201023 is an apocalyptic number.

21201201023 is a deficient number, since it is larger than the sum of its proper divisors (60748777).

21201201023 is an equidigital number, since it uses as much as digits as its factorization.

21201201023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60748776.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21201201023 its reverse (32010210212), we get a palindrome (53211411235).

The spelling of 21201201023 in words is "twenty-one billion, two hundred one million, two hundred one thousand, twenty-three".