21000131233 has 4 divisors (see below), whose sum is σ = 21001110208. Its totient is φ = 20999152260.

The previous prime is 21000131231. The next prime is 21000131237. The reversal of 21000131233 is 33213100012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21000131233 - 2¹ = 21000131231 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21000131231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 456573 + ... + 500458.

It is an arithmetic number, because the mean of its divisors is an integer number (5250277552).

Almost surely, 2^21000131233 is an apocalyptic number.

It is an amenable number.

21000131233 is a deficient number, since it is larger than the sum of its proper divisors (978975).

21000131233 is an equidigital number, since it uses as much as digits as its factorization.

21000131233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 978974.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21000131233 its reverse (33213100012), we get a palindrome (54213231245).

The spelling of 21000131233 in words is "twenty-one billion, one hundred thirty-one thousand, two hundred thirty-three".