1665251553210 has 128 divisors (see below), whose sum is σ = 4819704422400. Its totient is φ = 359713820160.

The previous prime is 1665251553197. The next prime is 1665251553221. The reversal of 1665251553210 is 123551525661.

It is a happy number.

It is a super-2 number, since 2×1665251553210² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 1121695 + ... + 2142125.

It is an arithmetic number, because the mean of its divisors is an integer number (37653940800).

Almost surely, 2^{1665251553210} is an apocalyptic number.

1665251553210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1665251553210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2409852211200).

1665251553210 is an abundant number, since it is smaller than the sum of its proper divisors (3154452869190).

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

1665251553210 is a wasteful number, since it uses less digits than its factorization.

1665251553210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020876.

The product of its (nonzero) digits is 270000, while the sum is 42.

The spelling of 1665251553210 in words is "one trillion, six hundred sixty-five billion, two hundred fifty-one million, five hundred fifty-three thousand, two hundred ten".