21836855217 has 8 divisors (see below), whose sum is σ = 29130753600. Its totient is φ = 14550430160.

The previous prime is 21836855197. The next prime is 21836855239. The reversal of 21836855217 is 71255863812.

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 21836855217 - 2⁶ = 21836855153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21836851217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1861509 + ... + 1873202.

It is an arithmetic number, because the mean of its divisors is an integer number (3641344200).

Almost surely, 2^21836855217 is an apocalyptic number.

It is an amenable number.

21836855217 is a deficient number, since it is larger than the sum of its proper divisors (7293898383).

21836855217 is a wasteful number, since it uses less digits than its factorization.

21836855217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3736663.

The product of its digits is 806400, while the sum is 48.

The spelling of 21836855217 in words is "twenty-one billion, eight hundred thirty-six million, eight hundred fifty-five thousand, two hundred seventeen".