21264040109 has 16 divisors (see below), whose sum is σ = 23901115392. Its totient is φ = 18770429568.

The previous prime is 21264040097. The next prime is 21264040117. The reversal of 21264040109 is 90104046212.

It is a cyclic number.

It is not a de Polignac number, because 21264040109 - 2⁴ = 21264040093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21264040139) 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, 2145764 + ... + 2155650.

It is an arithmetic number, because the mean of its divisors is an integer number (1493819712).

Almost surely, 2^21264040109 is an apocalyptic number.

It is an amenable number.

21264040109 is a deficient number, since it is larger than the sum of its proper divisors (2637075283).

21264040109 is a wasteful number, since it uses less digits than its factorization.

21264040109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17116.

The product of its (nonzero) digits is 3456, while the sum is 29.

The spelling of 21264040109 in words is "twenty-one billion, two hundred sixty-four million, forty thousand, one hundred nine".