51555257 has 4 divisors (see below), whose sum is σ = 55521060. Its totient is φ = 47589456.

The previous prime is 51555253. The next prime is 51555289. The reversal of 51555257 is 75255515.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10863616 + 40691641 = 3296^2 + 6379^2 .

It is a cyclic number.

It is not a de Polignac number, because 51555257 - 2² = 51555253 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51555253) 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, 1982882 + ... + 1982907.

It is an arithmetic number, because the mean of its divisors is an integer number (13880265).

Almost surely, 2^51555257 is an apocalyptic number.

It is an amenable number.

51555257 is a deficient number, since it is larger than the sum of its proper divisors (3965803).

51555257 is a wasteful number, since it uses less digits than its factorization.

51555257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3965802.

The product of its digits is 43750, while the sum is 35.

The square root of 51555257 is about 7180.1989526753. The cubic root of 51555257 is about 372.1839596751.

The spelling of 51555257 in words is "fifty-one million, five hundred fifty-five thousand, two hundred fifty-seven".