21791111145 has 16 divisors (see below), whose sum is σ = 36381681792. Its totient is φ = 11116624640.

The previous prime is 21791111143. The next prime is 21791111203. The reversal of 21791111145 is 54111119712.

It is not a de Polignac number, because 21791111145 - 2¹ = 21791111143 is a prime.

It is a super-2 number, since 2×21791111145² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21791111143) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31580976 + ... + 31581665.

It is an arithmetic number, because the mean of its divisors is an integer number (2273855112).

Almost surely, 2^21791111145 is an apocalyptic number.

It is an amenable number.

21791111145 is a deficient number, since it is larger than the sum of its proper divisors (14590570647).

21791111145 is a wasteful number, since it uses less digits than its factorization.

21791111145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63162672.

The product of its digits is 2520, while the sum is 33.

The spelling of 21791111145 in words is "twenty-one billion, seven hundred ninety-one million, one hundred eleven thousand, one hundred forty-five".