21371899233 has 4 divisors (see below), whose sum is σ = 28495865648. Its totient is φ = 14247932820.

The previous prime is 21371899223. The next prime is 21371899273. The reversal of 21371899233 is 33299817312.

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 not a de Polignac number, because 21371899233 - 2⁶ = 21371899169 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21371899223) 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, 3561983203 + ... + 3561983208.

It is an arithmetic number, because the mean of its divisors is an integer number (7123966412).

Almost surely, 2^21371899233 is an apocalyptic number.

It is an amenable number.

21371899233 is a deficient number, since it is larger than the sum of its proper divisors (7123966415).

21371899233 is an equidigital number, since it uses as much as digits as its factorization.

21371899233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7123966414.

The product of its digits is 489888, while the sum is 48.

The spelling of 21371899233 in words is "twenty-one billion, three hundred seventy-one million, eight hundred ninety-nine thousand, two hundred thirty-three".