51665187 has 16 divisors (see below), whose sum is σ = 79073280. Its totient is φ = 29393472.

The previous prime is 51665149. The next prime is 51665191. The reversal of 51665187 is 78156615.

It is not a de Polignac number, because 51665187 - 2⁸ = 51664931 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51665137) 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 15 ways as a sum of consecutive naturals, for example, 387 + ... + 10172.

It is an arithmetic number, because the mean of its divisors is an integer number (4942080).

Almost surely, 2^51665187 is an apocalyptic number.

51665187 is a deficient number, since it is larger than the sum of its proper divisors (27408093).

51665187 is a wasteful number, since it uses less digits than its factorization.

51665187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10802.

The product of its digits is 50400, while the sum is 39.

The square root of 51665187 is about 7187.8499566978. The cubic root of 51665187 is about 372.4483047640.

It can be divided in two parts, 516 and 65187, that added together give a triangular number (65703 = T₃₆₂).

The spelling of 51665187 in words is "fifty-one million, six hundred sixty-five thousand, one hundred eighty-seven".