66401340808 has 32 divisors (see below), whose sum is σ = 143810393760. Its totient is φ = 28406990080.

The previous prime is 66401340799. The next prime is 66401340827. The reversal of 66401340808 is 80804310466.

66401340808 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66401340808² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22191466 + ... + 22194457.

It is an arithmetic number, because the mean of its divisors is an integer number (4494074805).

Almost surely, 2^66401340808 is an apocalyptic number.

66401340808 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

66401340808 is an abundant number, since it is smaller than the sum of its proper divisors (77409052952).

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

66401340808 is a wasteful number, since it uses less digits than its factorization.

66401340808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44385957 (or 44385953 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 40.

The spelling of 66401340808 in words is "sixty-six billion, four hundred one million, three hundred forty thousand, eight hundred eight".