21262166065 has 16 divisors (see below), whose sum is σ = 29166393600. Its totient is φ = 14576345280.

The previous prime is 21262166063. The next prime is 21262166113. The reversal of 21262166065 is 56066126212.

It is not a de Polignac number, because 21262166065 - 2¹ = 21262166063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21262166063) 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, 84511 + ... + 222859.

It is an arithmetic number, because the mean of its divisors is an integer number (1822899600).

Almost surely, 2^21262166065 is an apocalyptic number.

It is an amenable number.

21262166065 is a deficient number, since it is larger than the sum of its proper divisors (7904227535).

21262166065 is a wasteful number, since it uses less digits than its factorization.

21262166065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142752.

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 21262166065 in words is "twenty-one billion, two hundred sixty-two million, one hundred sixty-six thousand, sixty-five".