51660121 has 4 divisors (see below), whose sum is σ = 51772644. Its totient is φ = 51547600.

The previous prime is 51660073. The next prime is 51660137. The reversal of 51660121 is 12106615.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 33512521 + 18147600 = 5789^2 + 4260^2 .

It is a cyclic number.

It is not a de Polignac number, because 51660121 - 2²¹ = 49562969 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51660092 and 51660101.

It is not an unprimeable number, because it can be changed into a prime (51660821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55570 + ... + 56491.

It is an arithmetic number, because the mean of its divisors is an integer number (12943161).

Almost surely, 2^51660121 is an apocalyptic number.

It is an amenable number.

51660121 is a deficient number, since it is larger than the sum of its proper divisors (112523).

51660121 is a wasteful number, since it uses less digits than its factorization.

51660121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112522.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 51660121 is about 7187.4975478257. The cubic root of 51660121 is about 372.4361309651.

Adding to 51660121 its reverse (12106615), we get a palindrome (63766736).

The spelling of 51660121 in words is "fifty-one million, six hundred sixty thousand, one hundred twenty-one".