21010020199 has 4 divisors (see below), whose sum is σ = 24011451664. Its totient is φ = 18008588736.

The previous prime is 21010020179. The next prime is 21010020223. The reversal of 21010020199 is 99102001012.

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 21010020199 - 2⁷ = 21010020071 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 (21010020179) 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, 1500715722 + ... + 1500715735.

It is an arithmetic number, because the mean of its divisors is an integer number (6002862916).

Almost surely, 2^21010020199 is an apocalyptic number.

21010020199 is a deficient number, since it is larger than the sum of its proper divisors (3001431465).

21010020199 is an equidigital number, since it uses as much as digits as its factorization.

21010020199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3001431464.

The product of its (nonzero) digits is 324, while the sum is 25.

The spelling of 21010020199 in words is "twenty-one billion, ten million, twenty thousand, one hundred ninety-nine".