21965120811 has 40 divisors (see below), whose sum is σ = 34012083600. Its totient is φ = 14109923520.

The previous prime is 21965120761. The next prime is 21965120831. The reversal of 21965120811 is 11802156912.

It is not a de Polignac number, because 21965120811 - 2¹³ = 21965112619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21965120831) 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 39 ways as a sum of consecutive naturals, for example, 1186456 + ... + 1204826.

It is an arithmetic number, because the mean of its divisors is an integer number (850302090).

Almost surely, 2^21965120811 is an apocalyptic number.

21965120811 is a deficient number, since it is larger than the sum of its proper divisors (12046962789).

21965120811 is a wasteful number, since it uses less digits than its factorization.

21965120811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18921 (or 18912 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 36.

The spelling of 21965120811 in words is "twenty-one billion, nine hundred sixty-five million, one hundred twenty thousand, eight hundred eleven".