66998161659 has 32 divisors (see below), whose sum is σ = 106668672768. Its totient is φ = 36867024000.

The previous prime is 66998161649. The next prime is 66998161709. The reversal of 66998161659 is 95616189966.

It is a happy number.

It is not a de Polignac number, because 66998161659 - 2⁹ = 66998161147 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66998161659.

It is not an unprimeable number, because it can be changed into a prime (66998161619) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1253937 + ... + 1306274.

It is an arithmetic number, because the mean of its divisors is an integer number (3333396024).

Almost surely, 2^66998161659 is an apocalyptic number.

66998161659 is a deficient number, since it is larger than the sum of its proper divisors (39670511109).

66998161659 is a wasteful number, since it uses less digits than its factorization.

66998161659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2560299.

The product of its digits is 37791360, while the sum is 66.

The spelling of 66998161659 in words is "sixty-six billion, nine hundred ninety-eight million, one hundred sixty-one thousand, six hundred fifty-nine".