51553666 has 8 divisors (see below), whose sum is σ = 77367420. Its totient is φ = 25764528.

The previous prime is 51553637. The next prime is 51553693. The reversal of 51553666 is 66635515.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 51538041 + 15625 = 7179^2 + 125^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 540 + ... + 10168.

Almost surely, 2^51553666 is an apocalyptic number.

51553666 is a deficient number, since it is larger than the sum of its proper divisors (25813754).

51553666 is a wasteful number, since it uses less digits than its factorization.

51553666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12308.

The product of its digits is 81000, while the sum is 37.

The square root of 51553666 is about 7180.0881610186. The cubic root of 51553666 is about 372.1801310919.

The spelling of 51553666 in words is "fifty-one million, five hundred fifty-three thousand, six hundred sixty-six".