21130203891 has 16 divisors (see below), whose sum is σ = 29896830720. Its totient is φ = 13245951840.

The previous prime is 21130203877. The next prime is 21130203893. The reversal of 21130203891 is 19830203112.

It is not a de Polignac number, because 21130203891 - 2¹⁰ = 21130202867 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21130203893) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2591140 + ... + 2599281.

It is an arithmetic number, because the mean of its divisors is an integer number (1868551920).

Almost surely, 2^21130203891 is an apocalyptic number.

21130203891 is a deficient number, since it is larger than the sum of its proper divisors (8766626829).

21130203891 is a wasteful number, since it uses less digits than its factorization.

21130203891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5190506.

The product of its (nonzero) digits is 2592, while the sum is 30.

The spelling of 21130203891 in words is "twenty-one billion, one hundred thirty million, two hundred three thousand, eight hundred ninety-one".