1665521343255 has 48 divisors (see below), whose sum is σ = 3381719048064. Its totient is φ = 692164710720.

The previous prime is 1665521343251. The next prime is 1665521343259. The reversal of 1665521343255 is 5523431255661.

It is an interprime number because it is at equal distance from previous prime (1665521343251) and next prime (1665521343259).

It is not a de Polignac number, because 1665521343255 - 2² = 1665521343251 is a prime.

It is a super-2 number, since 2×1665521343255² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665521343251) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 102992617 + ... + 103008786.

It is an arithmetic number, because the mean of its divisors is an integer number (70452480168).

Almost surely, 2^{1665521343255} is an apocalyptic number.

1665521343255 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1665521343255 is an abundant number, since it is smaller than the sum of its proper divisors (1716197704809).

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

1665521343255 is a wasteful number, since it uses less digits than its factorization.

1665521343255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206001436 (or 206001429 counting only the distinct ones).

The product of its digits is 3240000, while the sum is 48.

The spelling of 1665521343255 in words is "one trillion, six hundred sixty-five billion, five hundred twenty-one million, three hundred forty-three thousand, two hundred fifty-five".