21211311023 has 4 divisors (see below), whose sum is σ = 24241498320. Its totient is φ = 18181123728.

The previous prime is 21211311013. The next prime is 21211311041. The reversal of 21211311023 is 32011311212.

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 21211311023 - 2³² = 16916343727 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211310992 and 21211311010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211311013) 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, 1515093638 + ... + 1515093651.

It is an arithmetic number, because the mean of its divisors is an integer number (6060374580).

Almost surely, 2^21211311023 is an apocalyptic number.

21211311023 is a deficient number, since it is larger than the sum of its proper divisors (3030187297).

21211311023 is an equidigital number, since it uses as much as digits as its factorization.

21211311023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3030187296.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21211311023 its reverse (32011311212), we get a palindrome (53222622235).

The spelling of 21211311023 in words is "twenty-one billion, two hundred eleven million, three hundred eleven thousand, twenty-three".