66680781455 has 8 divisors (see below), whose sum is σ = 80025114672. Its totient is φ = 53339173888.

The previous prime is 66680781437. The next prime is 66680781467. The reversal of 66680781455 is 55418708666.

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 66680781455 - 2⁸ = 66680781199 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66680781455.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 627197 + ... + 725766.

It is an arithmetic number, because the mean of its divisors is an integer number (10003139334).

Almost surely, 2^66680781455 is an apocalyptic number.

66680781455 is a deficient number, since it is larger than the sum of its proper divisors (13344333217).

66680781455 is a wasteful number, since it uses less digits than its factorization.

66680781455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1362825.

The product of its (nonzero) digits is 9676800, while the sum is 56.

The spelling of 66680781455 in words is "sixty-six billion, six hundred eighty million, seven hundred eighty-one thousand, four hundred fifty-five".