21210200191 has 4 divisors (see below), whose sum is σ = 22132382832. Its totient is φ = 20288017552.

The previous prime is 21210200189. The next prime is 21210200201. The reversal of 21210200191 is 19100201212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21210200191 - 2¹ = 21210200189 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 (21210200111) 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, 461091286 + ... + 461091331.

It is an arithmetic number, because the mean of its divisors is an integer number (5533095708).

Almost surely, 2^21210200191 is an apocalyptic number.

21210200191 is a deficient number, since it is larger than the sum of its proper divisors (922182641).

21210200191 is an equidigital number, since it uses as much as digits as its factorization.

21210200191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 922182640.

The product of its (nonzero) digits is 72, while the sum is 19.

The spelling of 21210200191 in words is "twenty-one billion, two hundred ten million, two hundred thousand, one hundred ninety-one".