66521230356566 has 32 divisors (see below), whose sum is σ = 103095111813120. Its totient is φ = 32167018761696.

The previous prime is 66521230356551. The next prime is 66521230356583. The reversal of 66521230356566 is 66565303212566.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 855616691 + ... + 855694433.

It is an arithmetic number, because the mean of its divisors is an integer number (3221722244160).

Almost surely, 2^{66521230356566} is an apocalyptic number.

66521230356566 is a deficient number, since it is larger than the sum of its proper divisors (36573881456554).

66521230356566 is a wasteful number, since it uses less digits than its factorization.

66521230356566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147188.

The product of its (nonzero) digits is 34992000, while the sum is 56.

The spelling of 66521230356566 in words is "sixty-six trillion, five hundred twenty-one billion, two hundred thirty million, three hundred fifty-six thousand, five hundred sixty-six".