671545121 has 4 divisors (see below), whose sum is σ = 723202452. Its totient is φ = 619887792.

The previous prime is 671545117. The next prime is 671545123. The reversal of 671545121 is 121545176.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 376942225 + 294602896 = 19415^2 + 17164^2 .

It is a cyclic number.

It is not a de Polignac number, because 671545121 - 2² = 671545117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671545123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25828646 + ... + 25828671.

It is an arithmetic number, because the mean of its divisors is an integer number (180800613).

Almost surely, 2^671545121 is an apocalyptic number.

It is an amenable number.

671545121 is a deficient number, since it is larger than the sum of its proper divisors (51657331).

671545121 is a wasteful number, since it uses less digits than its factorization.

671545121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51657330.

The product of its digits is 8400, while the sum is 32.

The square root of 671545121 is about 25914.1876392064. The cubic root of 671545121 is about 875.7061493115.

Subtracting from 671545121 its reverse (121545176), we obtain a palindrome (549999945).

The spelling of 671545121 in words is "six hundred seventy-one million, five hundred forty-five thousand, one hundred twenty-one".