21201020101191 has 64 divisors (see below), whose sum is σ = 33208074547200. Its totient is φ = 11781747129600.

The previous prime is 21201020101159. The next prime is 21201020101193. The reversal of 21201020101191 is 19110102010212.

It is not a de Polignac number, because 21201020101191 - 2⁵ = 21201020101159 is a prime.

It is a super-2 number, since 2×21201020101191² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201020101193) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 48175056 + ... + 48613146.

It is an arithmetic number, because the mean of its divisors is an integer number (518876164800).

Almost surely, 2^{21201020101191} is an apocalyptic number.

21201020101191 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21201020101191 is a deficient number, since it is larger than the sum of its proper divisors (12007054446009).

21201020101191 is a wasteful number, since it uses less digits than its factorization.

21201020101191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438580.

The product of its (nonzero) digits is 72, while the sum is 21.

The spelling of 21201020101191 in words is "twenty-one trillion, two hundred one billion, twenty million, one hundred one thousand, one hundred ninety-one".