21766133129 has 4 divisors (see below), whose sum is σ = 23440451076. Its totient is φ = 20091815184.

The previous prime is 21766133101. The next prime is 21766133131. The reversal of 21766133129 is 92133166712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3037663225 + 18728469904 = 55115^2 + 136852^2 .

It is a cyclic number.

It is not a de Polignac number, because 21766133129 - 2²⁸ = 21497697673 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21766133029) 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, 837158954 + ... + 837158979.

It is an arithmetic number, because the mean of its divisors is an integer number (5860112769).

Almost surely, 2^21766133129 is an apocalyptic number.

It is an amenable number.

21766133129 is a deficient number, since it is larger than the sum of its proper divisors (1674317947).

21766133129 is a wasteful number, since it uses less digits than its factorization.

21766133129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1674317946.

The product of its digits is 81648, while the sum is 41.

The spelling of 21766133129 in words is "twenty-one billion, seven hundred sixty-six million, one hundred thirty-three thousand, one hundred twenty-nine".