6406521165660 has 192 divisors, whose sum is σ = 22370927846400. Its totient is φ = 1330847508480.

The previous prime is 6406521165647. The next prime is 6406521165719. The reversal of 6406521165660 is 665611256046.

It is a super-4 number, since 4×6406521165660⁴ (a number of 52 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 16238416 + ... + 16628264.

It is an arithmetic number, because the mean of its divisors is an integer number (116515249200).

Almost surely, 2^{6406521165660} is an apocalyptic number.

6406521165660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6406521165660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11185463923200).

6406521165660 is an abundant number, since it is smaller than the sum of its proper divisors (15964406680740).

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

6406521165660 is a wasteful number, since it uses less digits than its factorization.

6406521165660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393436 (or 393434 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 48.

The spelling of 6406521165660 in words is "six trillion, four hundred six billion, five hundred twenty-one million, one hundred sixty-five thousand, six hundred sixty".