21853545999 has 4 divisors (see below), whose sum is σ = 29138061336. Its totient is φ = 14569030664.

The previous prime is 21853545977. The next prime is 21853546003. The reversal of 21853545999 is 99954535812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21853545999 - 2¹³ = 21853537807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21853545199) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3642257664 + ... + 3642257669.

It is an arithmetic number, because the mean of its divisors is an integer number (7284515334).

Almost surely, 2^21853545999 is an apocalyptic number.

21853545999 is a deficient number, since it is larger than the sum of its proper divisors (7284515337).

21853545999 is an equidigital number, since it uses as much as digits as its factorization.

21853545999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7284515336.

The product of its digits is 17496000, while the sum is 60.

The spelling of 21853545999 in words is "twenty-one billion, eight hundred fifty-three million, five hundred forty-five thousand, nine hundred ninety-nine".