51985147 has 4 divisors (see below), whose sum is σ = 52149456. Its totient is φ = 51820840.

The previous prime is 51985097. The next prime is 51985163. The reversal of 51985147 is 74158915.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51985147 - 2⁷ = 51985019 is a prime.

It is a super-2 number, since 2×51985147² = 5404911017223218, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51985447) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81679 + ... + 82312.

It is an arithmetic number, because the mean of its divisors is an integer number (13037364).

Almost surely, 2^51985147 is an apocalyptic number.

51985147 is a deficient number, since it is larger than the sum of its proper divisors (164309).

51985147 is a wasteful number, since it uses less digits than its factorization.

51985147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164308.

The product of its digits is 50400, while the sum is 40.

The square root of 51985147 is about 7210.0726071240. The cubic root of 51985147 is about 373.2155744846.

The spelling of 51985147 in words is "fifty-one million, nine hundred eighty-five thousand, one hundred forty-seven".