51985199 has 4 divisors (see below), whose sum is σ = 59411664. Its totient is φ = 44558736.

The previous prime is 51985163. The next prime is 51985207. The reversal of 51985199 is 99158915.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99158915 = 5 ⋅19831783.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51985199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51985399) 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, 3713222 + ... + 3713235.

It is an arithmetic number, because the mean of its divisors is an integer number (14852916).

Almost surely, 2^51985199 is an apocalyptic number.

51985199 is a deficient number, since it is larger than the sum of its proper divisors (7426465).

51985199 is an equidigital number, since it uses as much as digits as its factorization.

51985199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7426464.

The product of its digits is 145800, while the sum is 47.

The square root of 51985199 is about 7210.0762131894. The cubic root of 51985199 is about 373.2156989253.

The spelling of 51985199 in words is "fifty-one million, nine hundred eighty-five thousand, one hundred ninety-nine".