21642243660535 has 16 divisors (see below), whose sum is σ = 26167700643840. Its totient is φ = 17182840692640.

The previous prime is 21642243660511. The next prime is 21642243660607. The reversal of 21642243660535 is 53506634224612.

It is not a de Polignac number, because 21642243660535 - 2²⁹ = 21641706789623 is a prime.

It is a super-4 number, since 4×21642243660535⁴ (a number of 54 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23586871 + ... + 24487240.

It is an arithmetic number, because the mean of its divisors is an integer number (1635481290240).

Almost surely, 2^{21642243660535} is an apocalyptic number.

21642243660535 is a deficient number, since it is larger than the sum of its proper divisors (4525456983305).

21642243660535 is a wasteful number, since it uses less digits than its factorization.

21642243660535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48074798.

The product of its (nonzero) digits is 6220800, while the sum is 49.

The spelling of 21642243660535 in words is "twenty-one trillion, six hundred forty-two billion, two hundred forty-three million, six hundred sixty thousand, five hundred thirty-five".