21040334399 has 16 divisors (see below), whose sum is σ = 25360346880. Its totient is φ = 17052534720.

The previous prime is 21040334389. The next prime is 21040334401. The reversal of 21040334399 is 99343304012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21040334399 - 2²⁰ = 21039285823 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 (21040334389) 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, 82529 + ... + 221114.

It is an arithmetic number, because the mean of its divisors is an integer number (1585021680).

Almost surely, 2^21040334399 is an apocalyptic number.

21040334399 is a deficient number, since it is larger than the sum of its proper divisors (4320012481).

21040334399 is a wasteful number, since it uses less digits than its factorization.

21040334399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304190.

The product of its (nonzero) digits is 69984, while the sum is 38.

The spelling of 21040334399 in words is "twenty-one billion, forty million, three hundred thirty-four thousand, three hundred ninety-nine".