21702265065 has 64 divisors (see below), whose sum is σ = 41642092800. Its totient is φ = 10660419072.

The previous prime is 21702265033. The next prime is 21702265141. The reversal of 21702265065 is 56056220712.

It is not a de Polignac number, because 21702265065 - 2⁵ = 21702265033 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 788506 + ... + 815564.

It is an arithmetic number, because the mean of its divisors is an integer number (650657700).

Almost surely, 2^21702265065 is an apocalyptic number.

It is an amenable number.

21702265065 is a deficient number, since it is larger than the sum of its proper divisors (19939827735).

21702265065 is a wasteful number, since it uses less digits than its factorization.

21702265065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27543 (or 27537 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

Adding to 21702265065 its reverse (56056220712), we get a palindrome (77758485777).

The spelling of 21702265065 in words is "twenty-one billion, seven hundred two million, two hundred sixty-five thousand, sixty-five".