66609171490 has 16 divisors (see below), whose sum is σ = 120189661560. Its totient is φ = 26578523520.

The previous prime is 66609171443. The next prime is 66609171493. The reversal of 66609171490 is 9417190666.

It can be written as a sum of positive squares in 4 ways, for example, as 66603737929 + 5433561 = 258077^2 + 2331^2 .

It is not an unprimeable number, because it can be changed into a prime (66609171493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8138841 + ... + 8147020.

Almost surely, 2^66609171490 is an apocalyptic number.

66609171490 is a deficient number, since it is larger than the sum of its proper divisors (53580490070).

66609171490 is a wasteful number, since it uses less digits than its factorization.

66609171490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16286277.

The product of its (nonzero) digits is 489888, while the sum is 49.

The spelling of 66609171490 in words is "sixty-six billion, six hundred nine million, one hundred seventy-one thousand, four hundred ninety".