66540511504477 has 2 divisors, whose sum is σ = 66540511504478. Its totient is φ = 66540511504476.

The previous prime is 66540511504471. The next prime is 66540511504661. The reversal of 66540511504477 is 77440511504566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63089755724836 + 3450755779641 = 7942906^2 + 1857621^2 .

It is a cyclic number.

It is not a de Polignac number, because 66540511504477 - 2⁷ = 66540511504349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66540511504471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33270255752238 + 33270255752239.

It is an arithmetic number, because the mean of its divisors is an integer number (33270255752239).

Almost surely, 2^{66540511504477} is an apocalyptic number.

It is an amenable number.

66540511504477 is a deficient number, since it is larger than the sum of its proper divisors (1).

66540511504477 is an equidigital number, since it uses as much as digits as its factorization.

66540511504477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14112000, while the sum is 55.

The spelling of 66540511504477 in words is "sixty-six trillion, five hundred forty billion, five hundred eleven million, five hundred four thousand, four hundred seventy-seven".