21652541663 has 16 divisors (see below), whose sum is σ = 22028196960. Its totient is φ = 21280444416.

The previous prime is 21652541641. The next prime is 21652541707. The reversal of 21652541663 is 36614525612.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21652541663 - 2¹⁰ = 21652540639 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21652541663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21652571663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19280420 + ... + 19281542.

It is an arithmetic number, because the mean of its divisors is an integer number (1376762310).

Almost surely, 2^21652541663 is an apocalyptic number.

21652541663 is a deficient number, since it is larger than the sum of its proper divisors (375655297).

21652541663 is a wasteful number, since it uses less digits than its factorization.

21652541663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2426.

The product of its digits is 259200, while the sum is 41.

The spelling of 21652541663 in words is "twenty-one billion, six hundred fifty-two million, five hundred forty-one thousand, six hundred sixty-three".