66831608221545 has 32 divisors (see below), whose sum is σ = 106974621936000. Its totient is φ = 35628844239360.

The previous prime is 66831608221513. The next prime is 66831608221571. The reversal of 66831608221545 is 54512280613866.

It is not a de Polignac number, because 66831608221545 - 2⁵ = 66831608221513 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 410560831 + ... + 410723579.

It is an arithmetic number, because the mean of its divisors is an integer number (3342956935500).

Almost surely, 2^{66831608221545} is an apocalyptic number.

It is an amenable number.

66831608221545 is a deficient number, since it is larger than the sum of its proper divisors (40143013714455).

66831608221545 is a wasteful number, since it uses less digits than its factorization.

66831608221545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173865.

The product of its (nonzero) digits is 16588800, while the sum is 57.

The spelling of 66831608221545 in words is "sixty-six trillion, eight hundred thirty-one billion, six hundred eight million, two hundred twenty-one thousand, five hundred forty-five".