51311985 has 8 divisors (see below), whose sum is σ = 82099200. Its totient is φ = 27366384.

The previous prime is 51311983. The next prime is 51311987. The reversal of 51311985 is 58911315.

It is an interprime number because it is at equal distance from previous prime (51311983) and next prime (51311987).

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

It is not a de Polignac number, because 51311985 - 2¹ = 51311983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51311983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1710385 + ... + 1710414.

It is an arithmetic number, because the mean of its divisors is an integer number (10262400).

Almost surely, 2^51311985 is an apocalyptic number.

It is an amenable number.

51311985 is a deficient number, since it is larger than the sum of its proper divisors (30787215).

51311985 is a wasteful number, since it uses less digits than its factorization.

51311985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3420807.

The product of its digits is 5400, while the sum is 33.

The square root of 51311985 is about 7163.2384436091. The cubic root of 51311985 is about 371.5976326389.

The spelling of 51311985 in words is "fifty-one million, three hundred eleven thousand, nine hundred eighty-five".