21001910001 has 4 divisors (see below), whose sum is σ = 28002546672. Its totient is φ = 14001273332.

The previous prime is 21001909969. The next prime is 21001910051. The reversal of 21001910001 is 10001910012.

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 21001910001 - 2⁵ = 21001909969 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21001910051) 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, 3500318331 + ... + 3500318336.

It is an arithmetic number, because the mean of its divisors is an integer number (7000636668).

Almost surely, 2^21001910001 is an apocalyptic number.

It is an amenable number.

21001910001 is a deficient number, since it is larger than the sum of its proper divisors (7000636671).

21001910001 is an equidigital number, since it uses as much as digits as its factorization.

21001910001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7000636670.

The product of its (nonzero) digits is 18, while the sum is 15.

The spelling of 21001910001 in words is "twenty-one billion, one million, nine hundred ten thousand, one".