66515478 has 16 divisors (see below), whose sum is σ = 133114800. Its totient is φ = 22157856.

The previous prime is 66515467. The next prime is 66515497. The reversal of 66515478 is 87451566.

It is a Curzon number.

It is a congruent number.

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, 12348 + ... + 16896.

It is an arithmetic number, because the mean of its divisors is an integer number (8319675).

Almost surely, 2^66515478 is an apocalyptic number.

66515478 is an abundant number, since it is smaller than the sum of its proper divisors (66599322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66515478 is a wasteful number, since it uses less digits than its factorization.

66515478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6991.

The product of its digits is 201600, while the sum is 42.

The square root of 66515478 is about 8155.7021770047. The cubic root of 66515478 is about 405.1733810307.

The spelling of 66515478 in words is "sixty-six million, five hundred fifteen thousand, four hundred seventy-eight".