51665385 has 32 divisors (see below), whose sum is σ = 86739840. Its totient is φ = 26224128.

The previous prime is 51665359. The next prime is 51665387. The reversal of 51665385 is 58356615.

51665385 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 51665385 - 2⁶ = 51665321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51665387) 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 31 ways as a sum of consecutive naturals, for example, 30942 + ... + 32568.

It is an arithmetic number, because the mean of its divisors is an integer number (2710620).

Almost surely, 2^51665385 is an apocalyptic number.

It is an amenable number.

51665385 is a deficient number, since it is larger than the sum of its proper divisors (35074455).

51665385 is a wasteful number, since it uses less digits than its factorization.

51665385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1737.

The product of its digits is 108000, while the sum is 39.

The square root of 51665385 is about 7187.8637299270. The cubic root of 51665385 is about 372.4487805497.

The spelling of 51665385 in words is "fifty-one million, six hundred sixty-five thousand, three hundred eighty-five".