51665205 has 16 divisors (see below), whose sum is σ = 82759680. Its totient is φ = 27523008.

The previous prime is 51665203. The next prime is 51665219. The reversal of 51665205 is 50256615.

It is not a de Polignac number, because 51665205 - 2¹ = 51665203 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51665203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17839 + ... + 20531.

It is an arithmetic number, because the mean of its divisors is an integer number (5172480).

Almost surely, 2^51665205 is an apocalyptic number.

It is an amenable number.

51665205 is a deficient number, since it is larger than the sum of its proper divisors (31094475).

51665205 is a wasteful number, since it uses less digits than its factorization.

51665205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3980.

The product of its (nonzero) digits is 9000, while the sum is 30.

The square root of 51665205 is about 7187.8512088106. The cubic root of 51665205 is about 372.4483480173.

The spelling of 51665205 in words is "fifty-one million, six hundred sixty-five thousand, two hundred five".