665553867264 has 960 divisors, whose sum is σ = 2360155607040. Its totient is φ = 183936614400.

The previous prime is 665553867089. The next prime is 665553867311. The reversal of 665553867264 is 462768355566.

665553867264 is a `hidden beast` number, since 6 + 6 + 5 + 553 + 8 + 6 + 72 + 6 + 4 = 666.

It is a super-2 number, since 2×665553867264² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2761634184 + ... + 2761634424.

It is an arithmetic number, because the mean of its divisors is an integer number (2458495424).

Almost surely, 2^665553867264 is an apocalyptic number.

665553867264 is a gapful number since it is divisible by the number (64) 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 665553867264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1180077803520).

665553867264 is an abundant number, since it is smaller than the sum of its proper divisors (1694601739776).

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

665553867264 is a wasteful number, since it uses less digits than its factorization.

665553867264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430 (or 397 counting only the distinct ones).

The product of its digits is 217728000, while the sum is 63.

The spelling of 665553867264 in words is "six hundred sixty-five billion, five hundred fifty-three million, eight hundred sixty-seven thousand, two hundred sixty-four".