21001031023 has 16 divisors (see below), whose sum is σ = 24200847360. Its totient is φ = 17851258656.

The previous prime is 21001030993. The next prime is 21001031063. The reversal of 21001031023 is 32013010012.

It is not a de Polignac number, because 21001031023 - 2⁵ = 21001030991 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001030994 and 21001031012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001031063) 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 in 15 ways as a sum of consecutive naturals, for example, 2950593 + ... + 2957701.

It is an arithmetic number, because the mean of its divisors is an integer number (1512552960).

Almost surely, 2^21001031023 is an apocalyptic number.

21001031023 is a deficient number, since it is larger than the sum of its proper divisors (3199816337).

21001031023 is a wasteful number, since it uses less digits than its factorization.

21001031023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10566.

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 21001031023 its reverse (32013010012), we get a palindrome (53014041035).

The spelling of 21001031023 in words is "twenty-one billion, one million, thirty-one thousand, twenty-three".