21744311961 has 16 divisors (see below), whose sum is σ = 29751986880. Its totient is φ = 14120358720.

The previous prime is 21744311957. The next prime is 21744312011. The reversal of 21744311961 is 16911344712.

It is not a de Polignac number, because 21744311961 - 2² = 21744311957 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21744311161) 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 15 ways as a sum of consecutive naturals, for example, 469830 + ... + 514031.

It is an arithmetic number, because the mean of its divisors is an integer number (1859499180).

Almost surely, 2^21744311961 is an apocalyptic number.

It is an amenable number.

21744311961 is a deficient number, since it is larger than the sum of its proper divisors (8007674919).

21744311961 is a wasteful number, since it uses less digits than its factorization.

21744311961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 984056.

The product of its digits is 36288, while the sum is 39.

The spelling of 21744311961 in words is "twenty-one billion, seven hundred forty-four million, three hundred eleven thousand, nine hundred sixty-one".