66277756401 has 16 divisors (see below), whose sum is σ = 93573957888. Its totient is φ = 41583660800.

The previous prime is 66277756397. The next prime is 66277756453. The reversal of 66277756401 is 10465777266.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 66277756401 - 2² = 66277756397 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (66277756001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1401736 + ... + 1448246.

It is an arithmetic number, because the mean of its divisors is an integer number (5848372368).

Almost surely, 2^66277756401 is an apocalyptic number.

It is an amenable number.

66277756401 is a deficient number, since it is larger than the sum of its proper divisors (27296201487).

66277756401 is a wasteful number, since it uses less digits than its factorization.

66277756401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74472.

The product of its (nonzero) digits is 2963520, while the sum is 51.

The spelling of 66277756401 in words is "sixty-six billion, two hundred seventy-seven million, seven hundred fifty-six thousand, four hundred one".