21654425605 has 8 divisors (see below), whose sum is σ = 26215269912. Its totient is φ = 17170234368.

The previous prime is 21654425593. The next prime is 21654425627. The reversal of 21654425605 is 50652445612.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3145639396 + 18508786209 = 56086^2 + 136047^2 .

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 21654425605 - 2¹³ = 21654417413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19162644 + ... + 19163773.

It is an arithmetic number, because the mean of its divisors is an integer number (3276908739).

Almost surely, 2^21654425605 is an apocalyptic number.

It is an amenable number.

21654425605 is a deficient number, since it is larger than the sum of its proper divisors (4560844307).

21654425605 is a wasteful number, since it uses less digits than its factorization.

21654425605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38326535.

The product of its (nonzero) digits is 288000, while the sum is 40.

The spelling of 21654425605 in words is "twenty-one billion, six hundred fifty-four million, four hundred twenty-five thousand, six hundred five".