21023001011 has 4 divisors (see below), whose sum is σ = 21047532792. Its totient is φ = 20998469232.

The previous prime is 21023000963. The next prime is 21023001017. The reversal of 21023001011 is 11010032012.

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 21023001011 - 2¹⁴ = 21022984627 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21023000983 and 21023001001.

It is not an unprimeable number, because it can be changed into a prime (21023001017) 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, 12264605 + ... + 12266318.

It is an arithmetic number, because the mean of its divisors is an integer number (5261883198).

Almost surely, 2^21023001011 is an apocalyptic number.

21023001011 is a deficient number, since it is larger than the sum of its proper divisors (24531781).

21023001011 is an equidigital number, since it uses as much as digits as its factorization.

21023001011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24531780.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21023001011 its reverse (11010032012), we get a palindrome (32033033023).

The spelling of 21023001011 in words is "twenty-one billion, twenty-three million, one thousand, eleven".