51665017 has 4 divisors (see below), whose sum is σ = 51713380. Its totient is φ = 51616656.

The previous prime is 51665011. The next prime is 51665021. The reversal of 51665017 is 71056615.

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 25563136 + 26101881 = 5056^2 + 5109^2 .

It is a cyclic number.

It is not a de Polignac number, because 51665017 - 2⁷ = 51664889 is a prime.

It is a super-2 number, since 2×51665017² = 5338547963220578, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51665017.

It is not an unprimeable number, because it can be changed into a prime (51665011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22542 + ... + 24727.

It is an arithmetic number, because the mean of its divisors is an integer number (12928345).

Almost surely, 2^51665017 is an apocalyptic number.

It is an amenable number.

51665017 is a deficient number, since it is larger than the sum of its proper divisors (48363).

51665017 is a wasteful number, since it uses less digits than its factorization.

51665017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48362.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 51665017 is about 7187.8381311769. The cubic root of 51665017 is about 372.4478962602.

The spelling of 51665017 in words is "fifty-one million, six hundred sixty-five thousand, seventeen".