21201040091 has 8 divisors (see below), whose sum is σ = 26432465664. Its totient is φ = 16520290920.

The previous prime is 21201040067. The next prime is 21201040109. The reversal of 21201040091 is 19004010212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21201040091 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21201040001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137669015 + ... + 137669168.

It is an arithmetic number, because the mean of its divisors is an integer number (3304058208).

Almost surely, 2^21201040091 is an apocalyptic number.

21201040091 is a deficient number, since it is larger than the sum of its proper divisors (5231425573).

21201040091 is a wasteful number, since it uses less digits than its factorization.

21201040091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275338201.

The product of its (nonzero) digits is 144, while the sum is 20.

The spelling of 21201040091 in words is "twenty-one billion, two hundred one million, forty thousand, ninety-one".