51001666 has 16 divisors (see below), whose sum is σ = 81135000. Its totient is φ = 23961600.

The previous prime is 51001619. The next prime is 51001729. The reversal of 51001666 is 66610015.

It can be written as a sum of positive squares in 4 ways, for example, as 31685641 + 19316025 = 5629^2 + 4395^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 51001666.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40210 + ... + 41458.

Almost surely, 2^51001666 is an apocalyptic number.

51001666 is a deficient number, since it is larger than the sum of its proper divisors (30133334).

51001666 is a wasteful number, since it uses less digits than its factorization.

51001666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2469.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 51001666 is about 7141.5450709213. The cubic root of 51001666 is about 370.8470149506.

The spelling of 51001666 in words is "fifty-one million, one thousand, six hundred sixty-six".