65161621 has 12 divisors (see below), whose sum is σ = 79790880. Its totient is φ = 52912440.

The previous prime is 65161619. The next prime is 65161633. The reversal of 65161621 is 12616156.

65161621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 65161621 - 2¹ = 65161619 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 65161621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65161651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34065 + ... + 35926.

It is an arithmetic number, because the mean of its divisors is an integer number (6649240).

Almost surely, 2^65161621 is an apocalyptic number.

It is an amenable number.

65161621 is a deficient number, since it is larger than the sum of its proper divisors (14629259).

65161621 is a wasteful number, since it uses less digits than its factorization.

65161621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70024 (or 70017 counting only the distinct ones).

The product of its digits is 2160, while the sum is 28.

The square root of 65161621 is about 8072.2748342707. The cubic root of 65161621 is about 402.4055480957.

Adding to 65161621 its reverse (12616156), we get a palindrome (77777777).

The spelling of 65161621 in words is "sixty-five million, one hundred sixty-one thousand, six hundred twenty-one".