21101220023 has 32 divisors (see below), whose sum is σ = 23736948480. Its totient is φ = 18630639360.

The previous prime is 21101220017. The next prime is 21101220043. The reversal of 21101220023 is 32002210112.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21101220023 - 2³⁰ = 20027478199 is a prime.

It is a super-2 number, since 2×21101220023² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101220043) 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 31 ways as a sum of consecutive naturals, for example, 16446140 + ... + 16447422.

It is an arithmetic number, because the mean of its divisors is an integer number (741779640).

Almost surely, 2^21101220023 is an apocalyptic number.

21101220023 is a deficient number, since it is larger than the sum of its proper divisors (2635728457).

21101220023 is a wasteful number, since it uses less digits than its factorization.

21101220023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1919.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21101220023 its reverse (32002210112), we get a palindrome (53103430135).

The spelling of 21101220023 in words is "twenty-one billion, one hundred one million, two hundred twenty thousand, twenty-three".