51363661 has 4 divisors (see below), whose sum is σ = 51378012. Its totient is φ = 51349312.

The previous prime is 51363617. The next prime is 51363673. The reversal of 51363661 is 16636315.

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 28419561 + 22944100 = 5331^2 + 4790^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51363661 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 (51363161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3075 + ... + 10591.

It is an arithmetic number, because the mean of its divisors is an integer number (12844503).

Almost surely, 2^51363661 is an apocalyptic number.

It is an amenable number.

51363661 is a deficient number, since it is larger than the sum of its proper divisors (14351).

51363661 is an equidigital number, since it uses as much as digits as its factorization.

51363661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14350.

The product of its digits is 9720, while the sum is 31.

The square root of 51363661 is about 7166.8445636835. The cubic root of 51363661 is about 371.7223353867.

Adding to 51363661 its reverse (16636315), we get a palindrome (67999976).

The spelling of 51363661 in words is "fifty-one million, three hundred sixty-three thousand, six hundred sixty-one".