21406927965 has 16 divisors (see below), whose sum is σ = 34372120128. Its totient is φ = 11376683136.

The previous prime is 21406927951. The next prime is 21406927967. The reversal of 21406927965 is 56972960412.

It is not a de Polignac number, because 21406927965 - 2¹⁵ = 21406895197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21406927967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2517184 + ... + 2525673.

It is an arithmetic number, because the mean of its divisors is an integer number (2148257508).

Almost surely, 2^21406927965 is an apocalyptic number.

It is an amenable number.

21406927965 is a deficient number, since it is larger than the sum of its proper divisors (12965192163).

21406927965 is a wasteful number, since it uses less digits than its factorization.

21406927965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5043148.

The product of its (nonzero) digits is 1632960, while the sum is 51.

The spelling of 21406927965 in words is "twenty-one billion, four hundred six million, nine hundred twenty-seven thousand, nine hundred sixty-five".