21593671653 has 4 divisors (see below), whose sum is σ = 28791562208. Its totient is φ = 14395781100.

The previous prime is 21593671621. The next prime is 21593671661. The reversal of 21593671653 is 35617639512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21593671653 - 2⁵ = 21593671621 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21593671663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3598945273 + ... + 3598945278.

It is an arithmetic number, because the mean of its divisors is an integer number (7197890552).

Almost surely, 2^21593671653 is an apocalyptic number.

It is an amenable number.

21593671653 is a deficient number, since it is larger than the sum of its proper divisors (7197890555).

21593671653 is an equidigital number, since it uses as much as digits as its factorization.

21593671653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7197890554.

The product of its digits is 1020600, while the sum is 48.

The spelling of 21593671653 in words is "twenty-one billion, five hundred ninety-three million, six hundred seventy-one thousand, six hundred fifty-three".