51505605 has 16 divisors (see below), whose sum is σ = 91565760. Its totient is φ = 27469584.

The previous prime is 51505603. The next prime is 51505609. The reversal of 51505605 is 50650515.

51505605 is a `hidden beast` number, since 5 + 1 + 50 + 5 + 605 = 666.

51505605 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51505605 - 2¹ = 51505603 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51505603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190627 + ... + 190896.

It is an arithmetic number, because the mean of its divisors is an integer number (5722860).

Almost surely, 2^51505605 is an apocalyptic number.

It is an amenable number.

51505605 is a deficient number, since it is larger than the sum of its proper divisors (40060155).

51505605 is a wasteful number, since it uses less digits than its factorization.

51505605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381537 (or 381531 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 27.

The square root of 51505605 is about 7176.7405554332. The cubic root of 51505605 is about 372.0644399293.

The spelling of 51505605 in words is "fifty-one million, five hundred five thousand, six hundred five".