664123516420 has 96 divisors (see below), whose sum is σ = 1756422759168. Its totient is φ = 205296118272.

The previous prime is 664123516411. The next prime is 664123516481. The reversal of 664123516420 is 24615321466.

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, 4164799 + ... + 4321318.

It is an arithmetic number, because the mean of its divisors is an integer number (18296070408).

Almost surely, 2^664123516420 is an apocalyptic number.

It is an amenable number.

664123516420 is an abundant number, since it is smaller than the sum of its proper divisors (1092299242748).

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

664123516420 is a wasteful number, since it uses less digits than its factorization.

664123516420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8486189 (or 8486187 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 40.

Adding to 664123516420 its reverse (24615321466), we get a palindrome (688738837886).

The spelling of 664123516420 in words is "six hundred sixty-four billion, one hundred twenty-three million, five hundred sixteen thousand, four hundred twenty".