51665506 has 4 divisors (see below), whose sum is σ = 77498262. Its totient is φ = 25832752.

The previous prime is 51665473. The next prime is 51665507. The reversal of 51665506 is 60556615.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 49829481 + 1836025 = 7059^2 + 1355^2 .

It is not an unprimeable number, because it can be changed into a prime (51665507) 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, 12916375 + ... + 12916378.

Almost surely, 2^51665506 is an apocalyptic number.

51665506 is a deficient number, since it is larger than the sum of its proper divisors (25832756).

51665506 is a wasteful number, since it uses less digits than its factorization.

51665506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25832755.

The product of its (nonzero) digits is 27000, while the sum is 34.

The square root of 51665506 is about 7187.8721468874. The cubic root of 51665506 is about 372.4490713070.

The spelling of 51665506 in words is "fifty-one million, six hundred sixty-five thousand, five hundred six".