65516121 has 60 divisors (see below), whose sum is σ = 112413840. Its totient is φ = 37707120.

The previous prime is 65516117. The next prime is 65516141. The reversal of 65516121 is 12161556.

It is a happy number.

65516121 is a `hidden beast` number, since 655 + 1 + 6 + 1 + 2 + 1 = 666.

It is not a de Polignac number, because 65516121 - 2² = 65516117 is a prime.

It is a super-2 number, since 2×65516121² = 8584724221773282, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (65516111) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 471270 + ... + 471408.

It is an arithmetic number, because the mean of its divisors is an integer number (1873564).

Almost surely, 2^65516121 is an apocalyptic number.

It is an amenable number.

65516121 is a deficient number, since it is larger than the sum of its proper divisors (46897719).

65516121 is a wasteful number, since it uses less digits than its factorization.

65516121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208 (or 176 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 65516121 is about 8094.2029255511. The cubic root of 65516121 is about 403.1339669179.

Adding to 65516121 its reverse (12161556), we get a palindrome (77677677).

The spelling of 65516121 in words is "sixty-five million, five hundred sixteen thousand, one hundred twenty-one".