51665473 has 2 divisors, whose sum is σ = 51665474. Its totient is φ = 51665472.

The previous prime is 51665461. The next prime is 51665507. The reversal of 51665473 is 37456615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26142769 + 25522704 = 5113^2 + 5052^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51665473 is a prime.

It is a super-2 number, since 2×51665473² = 5338642200627458, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51665413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25832736 + 25832737.

It is an arithmetic number, because the mean of its divisors is an integer number (25832737).

Almost surely, 2^51665473 is an apocalyptic number.

It is an amenable number.

51665473 is a deficient number, since it is larger than the sum of its proper divisors (1).

51665473 is an equidigital number, since it uses as much as digits as its factorization.

51665473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75600, while the sum is 37.

The square root of 51665473 is about 7187.8698513537. The cubic root of 51665473 is about 372.4489920096.

The spelling of 51665473 in words is "fifty-one million, six hundred sixty-five thousand, four hundred seventy-three".