21101021023 has 2 divisors, whose sum is σ = 21101021024. Its totient is φ = 21101021022.

The previous prime is 21101020991. The next prime is 21101021047. The reversal of 21101021023 is 32012010112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21101021023 - 2⁵ = 21101020991 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21101020994 and 21101021012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21101021323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550510511 + 10550510512.

It is an arithmetic number, because the mean of its divisors is an integer number (10550510512).

Almost surely, 2^21101021023 is an apocalyptic number.

21101021023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101021023 is an equidigital number, since it uses as much as digits as its factorization.

21101021023 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21101021023 its reverse (32012010112), we get a palindrome (53113031135).

The spelling of 21101021023 in words is "twenty-one billion, one hundred one million, twenty-one thousand, twenty-three".