21102043501 has 24 divisors (see below), whose sum is σ = 26787563136. Its totient is φ = 16437798720.

The previous prime is 21102043493. The next prime is 21102043507. The reversal of 21102043501 is 10534020112.

It is not a de Polignac number, because 21102043501 - 2³ = 21102043493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102043507) 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 23 ways as a sum of consecutive naturals, for example, 2781225 + ... + 2788801.

It is an arithmetic number, because the mean of its divisors is an integer number (1116148464).

Almost surely, 2^21102043501 is an apocalyptic number.

It is an amenable number.

21102043501 is a deficient number, since it is larger than the sum of its proper divisors (5685519635).

21102043501 is a wasteful number, since it uses less digits than its factorization.

21102043501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12769 (or 12762 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

Adding to 21102043501 its reverse (10534020112), we get a palindrome (31636063613).

The spelling of 21102043501 in words is "twenty-one billion, one hundred two million, forty-three thousand, five hundred one".