21761711161 has 4 divisors (see below), whose sum is σ = 22907064400. Its totient is φ = 20616357924.

The previous prime is 21761711149. The next prime is 21761711189. The reversal of 21761711161 is 16111716712.

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 21761711161 - 2⁵ = 21761711129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21761711131) 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, 572676591 + ... + 572676628.

It is an arithmetic number, because the mean of its divisors is an integer number (5726766100).

Almost surely, 2^21761711161 is an apocalyptic number.

It is an amenable number.

21761711161 is a deficient number, since it is larger than the sum of its proper divisors (1145353239).

21761711161 is a wasteful number, since it uses less digits than its factorization.

21761711161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1145353238.

The product of its digits is 3528, while the sum is 34.

The spelling of 21761711161 in words is "twenty-one billion, seven hundred sixty-one million, seven hundred eleven thousand, one hundred sixty-one".