21756004399 has 8 divisors (see below), whose sum is σ = 21813170688. Its totient is φ = 21698902680.

The previous prime is 21756004351. The next prime is 21756004411. The reversal of 21756004399 is 99340065712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21756004399 - 2¹⁷ = 21755873327 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 (21756004999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 699714 + ... + 730144.

It is an arithmetic number, because the mean of its divisors is an integer number (2726646336).

Almost surely, 2^21756004399 is an apocalyptic number.

21756004399 is a deficient number, since it is larger than the sum of its proper divisors (57166289).

21756004399 is a wasteful number, since it uses less digits than its factorization.

21756004399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32285.

The product of its (nonzero) digits is 408240, while the sum is 46.

The spelling of 21756004399 in words is "twenty-one billion, seven hundred fifty-six million, four thousand, three hundred ninety-nine".