66679956949599 has 72 divisors (see below), whose sum is σ = 116354930243760. Its totient is φ = 36645792325632.

The previous prime is 66679956949591. The next prime is 66679956949637. The reversal of 66679956949599 is 99594965997666.

It is not a de Polignac number, because 66679956949599 - 2³ = 66679956949591 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66679956949591) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 6856909 + ... + 13430454.

It is an arithmetic number, because the mean of its divisors is an integer number (1616040697830).

Almost surely, 2^{66679956949599} is an apocalyptic number.

66679956949599 is a deficient number, since it is larger than the sum of its proper divisors (49674973294161).

66679956949599 is a wasteful number, since it uses less digits than its factorization.

66679956949599 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20287669 (or 20287659 counting only the distinct ones).

The product of its digits is 482123275200, while the sum is 99.

The spelling of 66679956949599 in words is "sixty-six trillion, six hundred seventy-nine billion, nine hundred fifty-six million, nine hundred forty-nine thousand, five hundred ninety-nine".