51285257 has 4 divisors (see below), whose sum is σ = 51317760. Its totient is φ = 51252756.

The previous prime is 51285203. The next prime is 51285259. The reversal of 51285257 is 75258215.

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, and also an emirpimes, since its reverse is a distinct semiprime: 75258215 = 5 ⋅15051643.

It is a cyclic number.

It is not a de Polignac number, because 51285257 - 2⁸ = 51285001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51285259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13757 + ... + 17082.

It is an arithmetic number, because the mean of its divisors is an integer number (12829440).

Almost surely, 2^51285257 is an apocalyptic number.

It is an amenable number.

51285257 is a deficient number, since it is larger than the sum of its proper divisors (32503).

51285257 is a wasteful number, since it uses less digits than its factorization.

51285257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32502.

The product of its digits is 28000, while the sum is 35.

The square root of 51285257 is about 7161.3725639712. The cubic root of 51285257 is about 371.5331006942.

The spelling of 51285257 in words is "fifty-one million, two hundred eighty-five thousand, two hundred fifty-seven".