21950605911 has 16 divisors (see below), whose sum is σ = 31522235360. Its totient is φ = 13506600960.

The previous prime is 21950605907. The next prime is 21950605927. The reversal of 21950605911 is 11950605912.

It is not a de Polignac number, because 21950605911 - 2² = 21950605907 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21950605911.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21950605951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 416991 + ... + 466671.

It is an arithmetic number, because the mean of its divisors is an integer number (1970139710).

Almost surely, 2^21950605911 is an apocalyptic number.

21950605911 is a deficient number, since it is larger than the sum of its proper divisors (9571629449).

21950605911 is a wasteful number, since it uses less digits than its factorization.

21950605911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61026.

The product of its (nonzero) digits is 24300, while the sum is 39.

Subtracting from 21950605911 its reverse (11950605912), we obtain a palindrome (9999999999).

The spelling of 21950605911 in words is "twenty-one billion, nine hundred fifty million, six hundred five thousand, nine hundred eleven".