21101001993 has 12 divisors (see below), whose sum is σ = 30559650160. Its totient is φ = 14030215416.

The previous prime is 21101001947. The next prime is 21101002019. The reversal of 21101001993 is 39910010112.

It is not a de Polignac number, because 21101001993 - 2¹⁰ = 21101000969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101001293) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3089671 + ... + 3096492.

Almost surely, 2^21101001993 is an apocalyptic number.

It is an amenable number.

21101001993 is a deficient number, since it is larger than the sum of its proper divisors (9458648167).

21101001993 is a wasteful number, since it uses less digits than its factorization.

21101001993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6186548 (or 6186545 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 27.

It can be divided in two parts, 211010019 and 93, that added together give a palindrome (211010112).

The spelling of 21101001993 in words is "twenty-one billion, one hundred one million, one thousand, nine hundred ninety-three".