4165521345 has 24 divisors (see below), whose sum is σ = 7228728936. Its totient is φ = 2218998528.

The previous prime is 4165521341. The next prime is 4165521377. The reversal of 4165521345 is 5431255614.

4165521345 is a `hidden beast` number, since 41 + 65 + 521 + 34 + 5 = 666.

4165521345 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 1789543809 + 2375977536 = 42303^2 + 48744^2 .

It is not a de Polignac number, because 4165521345 - 2² = 4165521341 is a prime.

It is not an unprimeable number, because it can be changed into a prime (4165521341) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15442 + ... + 92571.

It is an arithmetic number, because the mean of its divisors is an integer number (301197039).

Almost surely, 2^4165521345 is an apocalyptic number.

4165521345 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

4165521345 is a deficient number, since it is larger than the sum of its proper divisors (3063207591).

4165521345 is a wasteful number, since it uses less digits than its factorization.

4165521345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108881 (or 108878 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The square root of 4165521345 is about 64540.8502035726. The cubic root of 4165521345 is about 1609.0015213766.

Adding to 4165521345 its reverse (5431255614), we get a palindrome (9596776959).

The spelling of 4165521345 in words is "four billion, one hundred sixty-five million, five hundred twenty-one thousand, three hundred forty-five".