66910043655 has 384 divisors, whose sum is σ = 162041241600. Its totient is φ = 25866086400.

The previous prime is 66910043639. The next prime is 66910043671. The reversal of 66910043655 is 55634001966.

66910043655 is a `hidden beast` number, since 6 + 69 + 100 + 436 + 55 = 666.

66910043655 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (66910043639) and next prime (66910043671).

It is not a de Polignac number, because 66910043655 - 2⁴ = 66910043639 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 66910043655.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 50650395 + ... + 50651715.

It is an arithmetic number, because the mean of its divisors is an integer number (421982400).

Almost surely, 2^66910043655 is an apocalyptic number.

66910043655 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

66910043655 is an abundant number, since it is smaller than the sum of its proper divisors (95131197945).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66910043655 is a wasteful number, since it uses less digits than its factorization.

66910043655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1412 (or 1399 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 45.

The spelling of 66910043655 in words is "sixty-six billion, nine hundred ten million, forty-three thousand, six hundred fifty-five".