665266661165400 has 384 divisors, whose sum is σ = 2380655310451200. Its totient is φ = 150531710976000.

The previous prime is 665266661165369. The next prime is 665266661165413. The reversal of 665266661165400 is 4561166662566.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

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, 2769481699 + ... + 2769721901.

It is an arithmetic number, because the mean of its divisors is an integer number (6199623204300).

Almost surely, 2^{665266661165400} is an apocalyptic number.

665266661165400 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 665266661165400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1190327655225600).

665266661165400 is an abundant number, since it is smaller than the sum of its proper divisors (1715388649285800).

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

665266661165400 is a wasteful number, since it uses less digits than its factorization.

665266661165400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246859 (or 246850 counting only the distinct ones).

The product of its (nonzero) digits is 55987200, while the sum is 60.

The spelling of 665266661165400 in words is "six hundred sixty-five trillion, two hundred sixty-six billion, six hundred sixty-one million, one hundred sixty-five thousand, four hundred".