666081205464 has 128 divisors (see below), whose sum is σ = 1706140800000. Its totient is φ = 216634176000.

The previous prime is 666081205411. The next prime is 666081205519. The reversal of 666081205464 is 464502180666.

It is a congruent number.

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, 101672989 + ... + 101679539.

It is an arithmetic number, because the mean of its divisors is an integer number (13329225000).

Almost surely, 2^666081205464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666081205464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (853070400000).

666081205464 is an abundant number, since it is smaller than the sum of its proper divisors (1040059594536).

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

666081205464 is a wasteful number, since it uses less digits than its factorization.

666081205464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7169 (or 7165 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 48.

The spelling of 666081205464 in words is "six hundred sixty-six billion, eighty-one million, two hundred five thousand, four hundred sixty-four".