16405555664 has 80 divisors (see below), whose sum is σ = 33912829440. Its totient is φ = 7674240000.

The previous prime is 16405555657. The next prime is 16405555687. The reversal of 16405555664 is 46655550461.

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, 2869769 + ... + 2875479.

It is an arithmetic number, because the mean of its divisors is an integer number (423910368).

Almost surely, 2^16405555664 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 16405555664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16956414720).

16405555664 is an abundant number, since it is smaller than the sum of its proper divisors (17507273776).

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

16405555664 is a wasteful number, since it uses less digits than its factorization.

16405555664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5940 (or 5934 counting only the distinct ones).

The product of its (nonzero) digits is 2160000, while the sum is 47.

The spelling of 16405555664 in words is "sixteen billion, four hundred five million, five hundred fifty-five thousand, six hundred sixty-four".