21111021023 has 2 divisors, whose sum is σ = 21111021024. Its totient is φ = 21111021022.

The previous prime is 21111021013. The next prime is 21111021031. The reversal of 21111021023 is 32012011112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21111021023 - 2²⁸ = 20842585567 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21111020989 and 21111021007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111021013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555510511 + 10555510512.

It is an arithmetic number, because the mean of its divisors is an integer number (10555510512).

Almost surely, 2^21111021023 is an apocalyptic number.

21111021023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111021023 is an equidigital number, since it uses as much as digits as its factorization.

21111021023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21111021023 its reverse (32012011112), we get a palindrome (53123032135).

The spelling of 21111021023 in words is "twenty-one billion, one hundred eleven million, twenty-one thousand, twenty-three".