21586259609 has 4 divisors (see below), whose sum is σ = 22856039604. Its totient is φ = 20316479616.

The previous prime is 21586259573. The next prime is 21586259641. The reversal of 21586259609 is 90695268512.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6752237584 + 14834022025 = 82172^2 + 121795^2 .

It is a cyclic number.

It is not a de Polignac number, because 21586259609 - 2¹⁶ = 21586194073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21586259809) 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, 634889972 + ... + 634890005.

It is an arithmetic number, because the mean of its divisors is an integer number (5714009901).

Almost surely, 2^21586259609 is an apocalyptic number.

It is an amenable number.

21586259609 is a deficient number, since it is larger than the sum of its proper divisors (1269779995).

21586259609 is a wasteful number, since it uses less digits than its factorization.

21586259609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1269779994.

The product of its (nonzero) digits is 2332800, while the sum is 53.

The spelling of 21586259609 in words is "twenty-one billion, five hundred eighty-six million, two hundred fifty-nine thousand, six hundred nine".