21857652089 has 32 divisors (see below), whose sum is σ = 27848862720. Its totient is φ = 16685932032.

The previous prime is 21857652049. The next prime is 21857652109. The reversal of 21857652089 is 98025675812.

It is not a de Polignac number, because 21857652089 - 2²⁴ = 21840874873 is a prime.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21857652089.

It is not an unprimeable number, because it can be changed into a prime (21857652049) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6709349 + ... + 6712605.

It is an arithmetic number, because the mean of its divisors is an integer number (870276960).

Almost surely, 2^21857652089 is an apocalyptic number.

21857652089 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21857652089 is a deficient number, since it is larger than the sum of its proper divisors (5991210631).

21857652089 is a wasteful number, since it uses less digits than its factorization.

21857652089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5849.

The product of its (nonzero) digits is 2419200, while the sum is 53.

The spelling of 21857652089 in words is "twenty-one billion, eight hundred fifty-seven million, six hundred fifty-two thousand, eighty-nine".