65610260021 has 4 divisors (see below), whose sum is σ = 65610841932. Its totient is φ = 65609678112.

The previous prime is 65610260017. The next prime is 65610260033. The reversal of 65610260021 is 12006201656.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 24790502500 + 40819757521 = 157450^2 + 202039^2 .

It is a cyclic number.

It is not a de Polignac number, because 65610260021 - 2² = 65610260017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65610260041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61526 + ... + 367431.

It is an arithmetic number, because the mean of its divisors is an integer number (16402710483).

Almost surely, 2^65610260021 is an apocalyptic number.

It is an amenable number.

65610260021 is a deficient number, since it is larger than the sum of its proper divisors (581911).

65610260021 is a wasteful number, since it uses less digits than its factorization.

65610260021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581910.

The product of its (nonzero) digits is 4320, while the sum is 29.

Adding to 65610260021 its reverse (12006201656), we get a palindrome (77616461677).

The spelling of 65610260021 in words is "sixty-five billion, six hundred ten million, two hundred sixty thousand, twenty-one".