66559147907641 has 27 divisors (see below), whose sum is σ = 67822491845997. Its totient is φ = 65319245625600.

The previous prime is 66559147907599. The next prime is 66559147907657. The reversal of 66559147907641 is 14670974195566.

The square root of 66559147907641 is 8158379.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 17342468896041 + 49216679011600 = 4164429^2 + 7015460^2 .

It is not a de Polignac number, because 66559147907641 - 2³⁹ = 66009392093753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66559147907141) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 119495776935 + ... + 119495777491.

Almost surely, 2^{66559147907641} is an apocalyptic number.

66559147907641 is the 8158379-th square number.

66559147907641 is the 4079190-th centered octagonal number.

It is an amenable number.

66559147907641 is a deficient number, since it is larger than the sum of its proper divisors (1263343938356).

66559147907641 is an frugal number, since it uses more digits than its factorization.

66559147907641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1610 (or 805 counting only the distinct ones).

The product of its (nonzero) digits is 342921600, while the sum is 70.

The spelling of 66559147907641 in words is "sixty-six trillion, five hundred fifty-nine billion, one hundred forty-seven million, nine hundred seven thousand, six hundred forty-one".