21961942771 has 8 divisors (see below), whose sum is σ = 23033143584. Its totient is φ = 20900436480.

The previous prime is 21961942747. The next prime is 21961942799. The reversal of 21961942771 is 17724916912.

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

It is a cyclic number.

It is not a de Polignac number, because 21961942771 - 2¹⁹ = 21961418483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21961942571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2418990 + ... + 2428051.

It is an arithmetic number, because the mean of its divisors is an integer number (2879142948).

Almost surely, 2^21961942771 is an apocalyptic number.

21961942771 is a deficient number, since it is larger than the sum of its proper divisors (1071200813).

21961942771 is a wasteful number, since it uses less digits than its factorization.

21961942771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4847261.

The product of its digits is 381024, while the sum is 49.

The spelling of 21961942771 in words is "twenty-one billion, nine hundred sixty-one million, nine hundred forty-two thousand, seven hundred seventy-one".