66701620665 has 128 divisors (see below), whose sum is σ = 130170240000. Its totient is φ = 32256258048.

The previous prime is 66701620627. The next prime is 66701620691. The reversal of 66701620665 is 56602610766.

It is not a de Polignac number, because 66701620665 - 2¹³ = 66701612473 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 66701620665.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 43060311 + ... + 43061859.

It is an arithmetic number, because the mean of its divisors is an integer number (1016955000).

Almost surely, 2^66701620665 is an apocalyptic number.

It is an amenable number.

66701620665 is a deficient number, since it is larger than the sum of its proper divisors (63468619335).

66701620665 is a wasteful number, since it uses less digits than its factorization.

66701620665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2256 (or 2250 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 66701620665 in words is "sixty-six billion, seven hundred one million, six hundred twenty thousand, six hundred sixty-five".