51633665 has 4 divisors (see below), whose sum is σ = 61960404. Its totient is φ = 41306928.

The previous prime is 51633649. The next prime is 51633667. The reversal of 51633665 is 56633615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56633615 = 5 ⋅11326723.

It can be written as a sum of positive squares in 2 ways, for example, as 40551424 + 11082241 = 6368^2 + 3329^2 .

It is a cyclic number.

It is not a de Polignac number, because 51633665 - 2⁴ = 51633649 is a prime.

It is a super-2 number, since 2×51633665² = 5332070722664450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51633667) 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, 5163362 + ... + 5163371.

It is an arithmetic number, because the mean of its divisors is an integer number (15490101).

Almost surely, 2^51633665 is an apocalyptic number.

It is an amenable number.

51633665 is a deficient number, since it is larger than the sum of its proper divisors (10326739).

51633665 is a wasteful number, since it uses less digits than its factorization.

51633665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10326738.

The product of its digits is 48600, while the sum is 35.

The square root of 51633665 is about 7185.6568941190. The cubic root of 51633665 is about 372.3725432140.

The spelling of 51633665 in words is "fifty-one million, six hundred thirty-three thousand, six hundred sixty-five".