51687251 has 32 divisors (see below), whose sum is σ = 67737600. Its totient is φ = 38263680.

The previous prime is 51687241. The next prime is 51687253. The reversal of 51687251 is 15278615.

It is not a de Polignac number, because 51687251 - 2¹⁰ = 51686227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51687253) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 176261 + ... + 176553.

It is an arithmetic number, because the mean of its divisors is an integer number (2116800).

Almost surely, 2^51687251 is an apocalyptic number.

51687251 is a deficient number, since it is larger than the sum of its proper divisors (16050349).

51687251 is a wasteful number, since it uses less digits than its factorization.

51687251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419.

The product of its digits is 16800, while the sum is 35.

The square root of 51687251 is about 7189.3846050966. The cubic root of 51687251 is about 372.5013161523.

The spelling of 51687251 in words is "fifty-one million, six hundred eighty-seven thousand, two hundred fifty-one".