51661637 has 2 divisors, whose sum is σ = 51661638. Its totient is φ = 51661636.

The previous prime is 51661613. The next prime is 51661651. The reversal of 51661637 is 73616615.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49547521 + 2114116 = 7039^2 + 1454^2 .

It is a cyclic number.

It is not a de Polignac number, because 51661637 - 2¹⁰ = 51660613 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 51661597 and 51661606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51661667) 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 as a sum of consecutive naturals, namely, 25830818 + 25830819.

It is an arithmetic number, because the mean of its divisors is an integer number (25830819).

Almost surely, 2^51661637 is an apocalyptic number.

It is an amenable number.

51661637 is a deficient number, since it is larger than the sum of its proper divisors (1).

51661637 is an equidigital number, since it uses as much as digits as its factorization.

51661637 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22680, while the sum is 35.

The square root of 51661637 is about 7187.6030079575. The cubic root of 51661637 is about 372.4397740567.

The spelling of 51661637 in words is "fifty-one million, six hundred sixty-one thousand, six hundred thirty-seven".