165591211041 has 81 divisors (see below), whose sum is σ = 259914924633. Its totient is φ = 101569478400.

The previous prime is 165591211021. The next prime is 165591211057. The reversal of 165591211041 is 140112195561.

It is a happy number.

The square root of 165591211041 is 406929.

It is a perfect power (a square), and thus also a powerful number.

165591211041 is a `hidden beast` number, since 1 + 6 + 5 + 591 + 21 + 1 + 0 + 41 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 98611700625 + 66979510416 = 314025^2 + 258804^2 .

It is not a de Polignac number, because 165591211041 - 2⁷ = 165591210913 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 165591210987 and 165591211005.

It is not an unprimeable number, because it can be changed into a prime (165591211021) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 1639516891 + ... + 1639516991.

Almost surely, 2^165591211041 is an apocalyptic number.

165591211041 is the 406929-th square number.

165591211041 is the 203465-th centered octagonal number.

It is an amenable number.

165591211041 is a deficient number, since it is larger than the sum of its proper divisors (94323713592).

165591211041 is an equidigital number, since it uses as much as digits as its factorization.

165591211041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 36.

Multiplying 165591211041 by its sum of digits (36), we get a square (5961283597476 = 2441574²).

The spelling of 165591211041 in words is "one hundred sixty-five billion, five hundred ninety-one million, two hundred eleven thousand, forty-one".