51999973 has 4 divisors (see below), whose sum is σ = 52776160. Its totient is φ = 51223788.

The previous prime is 51999971. The next prime is 52000007. The reversal of 51999973 is 37999915.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51999973 - 2¹ = 51999971 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51999973.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51999971) 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, 387993 + ... + 388126.

It is an arithmetic number, because the mean of its divisors is an integer number (13194040).

Almost surely, 2^51999973 is an apocalyptic number.

It is an amenable number.

51999973 is a deficient number, since it is larger than the sum of its proper divisors (776187).

51999973 is an equidigital number, since it uses as much as digits as its factorization.

51999973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776186.

The product of its digits is 688905, while the sum is 52.

The square root of 51999973 is about 7211.1006788146. The cubic root of 51999973 is about 373.2510510806.

Adding to 51999973 its sum of digits (52), we get a palindrome (52000025).

The spelling of 51999973 in words is "fifty-one million, nine hundred ninety-nine thousand, nine hundred seventy-three".