65161225521 has 48 divisors (see below), whose sum is σ = 113011610880. Its totient is φ = 36997702560.

The previous prime is 65161225499. The next prime is 65161225523. The reversal of 65161225521 is 12552216156.

65161225521 is a `hidden beast` number, since 6 + 5 + 1 + 6 + 122 + 5 + 521 = 666.

It is not a de Polignac number, because 65161225521 - 2¹⁵ = 65161192753 is a prime.

It is a super-2 number, since 2×65161225521² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (65161225523) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 50856 + ... + 364566.

It is an arithmetic number, because the mean of its divisors is an integer number (2354408560).

Almost surely, 2^65161225521 is an apocalyptic number.

It is an amenable number.

65161225521 is a deficient number, since it is larger than the sum of its proper divisors (47850385359).

65161225521 is a wasteful number, since it uses less digits than its factorization.

65161225521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313891 (or 313878 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The spelling of 65161225521 in words is "sixty-five billion, one hundred sixty-one million, two hundred twenty-five thousand, five hundred twenty-one".