66681340019 has 8 divisors (see below), whose sum is σ = 76503774048. Its totient is φ = 56933038080.

The previous prime is 66681339961. The next prime is 66681340021. The reversal of 66681340019 is 91004318666.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66681340019 - 2¹² = 66681335923 is a prime.

It is a super-2 number, since 2×66681340019² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66681340079) 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, 18531092 + ... + 18534689.

It is an arithmetic number, because the mean of its divisors is an integer number (9562971756).

Almost surely, 2^66681340019 is an apocalyptic number.

66681340019 is a deficient number, since it is larger than the sum of its proper divisors (9822434029).

66681340019 is a wasteful number, since it uses less digits than its factorization.

66681340019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37066045.

The product of its (nonzero) digits is 186624, while the sum is 44.

The spelling of 66681340019 in words is "sixty-six billion, six hundred eighty-one million, three hundred forty thousand, nineteen".