66751647919 has 4 divisors (see below), whose sum is σ = 72819979560. Its totient is φ = 60683316280.

The previous prime is 66751647889. The next prime is 66751647923. The reversal of 66751647919 is 91974615766.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66751647919 - 2⁹ = 66751647407 is a prime.

It is a super-2 number, since 2×66751647919² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66751647119) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3034165804 + ... + 3034165825.

It is an arithmetic number, because the mean of its divisors is an integer number (18204994890).

Almost surely, 2^66751647919 is an apocalyptic number.

66751647919 is a deficient number, since it is larger than the sum of its proper divisors (6068331641).

66751647919 is a wasteful number, since it uses less digits than its factorization.

66751647919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6068331640.

The product of its digits is 17146080, while the sum is 61.

The spelling of 66751647919 in words is "sixty-six billion, seven hundred fifty-one million, six hundred forty-seven thousand, nine hundred nineteen".