21236375811 has 64 divisors (see below), whose sum is σ = 34821570560. Its totient is φ = 11254826880.

The previous prime is 21236375747. The next prime is 21236375819. The reversal of 21236375811 is 11857363212.

It is a happy number.

It is not a de Polignac number, because 21236375811 - 2⁶ = 21236375747 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21236375811.

It is not an unprimeable number, because it can be changed into a prime (21236375819) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1607250 + ... + 1620408.

It is an arithmetic number, because the mean of its divisors is an integer number (544087040).

Almost surely, 2^21236375811 is an apocalyptic number.

21236375811 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21236375811 is a deficient number, since it is larger than the sum of its proper divisors (13585194749).

21236375811 is a wasteful number, since it uses less digits than its factorization.

21236375811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13304.

The product of its digits is 60480, while the sum is 39.

The spelling of 21236375811 in words is "twenty-one billion, two hundred thirty-six million, three hundred seventy-five thousand, eight hundred eleven".