66670000039991 has 16 divisors (see below), whose sum is σ = 68437058844000. Its totient is φ = 64909669317120.

The previous prime is 66670000039969. The next prime is 66670000040047. The reversal of 66670000039991 is 19993000007666.

It is a cyclic number.

It is not a de Polignac number, because 66670000039991 - 2¹⁸ = 66669999777847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66670000039921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 377523485 + ... + 377700041.

It is an arithmetic number, because the mean of its divisors is an integer number (4277316177750).

Almost surely, 2^{66670000039991} is an apocalyptic number.

66670000039991 is a deficient number, since it is larger than the sum of its proper divisors (1767058804009).

66670000039991 is a wasteful number, since it uses less digits than its factorization.

66670000039991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195554.

The product of its (nonzero) digits is 3306744, while the sum is 56.

The spelling of 66670000039991 in words is "sixty-six trillion, six hundred seventy billion, thirty-nine thousand, nine hundred ninety-one".