66400064064220 has 48 divisors (see below), whose sum is σ = 149435255850048. Its totient is φ = 24718613736960.

The previous prime is 66400064064181. The next prime is 66400064064239. The reversal of 66400064064220 is 2246046000466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1950631161 + ... + 1950665200.

It is an arithmetic number, because the mean of its divisors is an integer number (3113234496876).

Almost surely, 2^{66400064064220} is an apocalyptic number.

It is an amenable number.

66400064064220 is an abundant number, since it is smaller than the sum of its proper divisors (83035191785828).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66400064064220 is a wasteful number, since it uses less digits than its factorization.

66400064064220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3901296430 (or 3901296428 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 40.

The spelling of 66400064064220 in words is "sixty-six trillion, four hundred billion, sixty-four million, sixty-four thousand, two hundred twenty".