51501605506 has 8 divisors (see below), whose sum is σ = 83194901244. Its totient is φ = 23769971760.

The previous prime is 51501605501. The next prime is 51501605563. The reversal of 51501605506 is 60550610515.

It can be written as a sum of positive squares in 2 ways, for example, as 37378422225 + 14123183281 = 193335^2 + 118841^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (51501605501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 990415465 + ... + 990415516.

Almost surely, 2^51501605506 is an apocalyptic number.

51501605506 is a deficient number, since it is larger than the sum of its proper divisors (31693295738).

51501605506 is a wasteful number, since it uses less digits than its factorization.

51501605506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1980830996.

The product of its (nonzero) digits is 22500, while the sum is 34.

The spelling of 51501605506 in words is "fifty-one billion, five hundred one million, six hundred five thousand, five hundred six".