51005506 has 4 divisors (see below), whose sum is σ = 76508262. Its totient is φ = 25502752.

The previous prime is 51005503. The next prime is 51005533. The reversal of 51005506 is 60550015.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60550015 = 5 ⋅12110003.

It can be written as a sum of positive squares in only one way, i.e., 26946481 + 24059025 = 5191^2 + 4905^2 .

It is not an unprimeable number, because it can be changed into a prime (51005503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12751375 + ... + 12751378.

Almost surely, 2^51005506 is an apocalyptic number.

51005506 is a deficient number, since it is larger than the sum of its proper divisors (25502756).

51005506 is a wasteful number, since it uses less digits than its factorization.

51005506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25502755.

The product of its (nonzero) digits is 750, while the sum is 22.

The square root of 51005506 is about 7141.8139152459. The cubic root of 51005506 is about 370.8563219459.

The spelling of 51005506 in words is "fifty-one million, five thousand, five hundred six".