661025133 has 6 divisors (see below), whose sum is σ = 954814094. Its totient is φ = 440683416.

The previous prime is 661025117. The next prime is 661025179. The reversal of 661025133 is 331520166.

It can be written as a sum of positive squares in only one way, i.e., 623900484 + 37124649 = 24978^2 + 6093^2 .

It is not a de Polignac number, because 661025133 - 2⁴ = 661025117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661025097 and 661025106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661025033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36723610 + ... + 36723627.

Almost surely, 2^661025133 is an apocalyptic number.

It is an amenable number.

661025133 is a deficient number, since it is larger than the sum of its proper divisors (293788961).

661025133 is a wasteful number, since it uses less digits than its factorization.

661025133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73447243 (or 73447240 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 661025133 is about 25710.4090399200. The cubic root of 661025133 is about 871.1093142318.

Adding to 661025133 its reverse (331520166), we get a palindrome (992545299).

The spelling of 661025133 in words is "six hundred sixty-one million, twenty-five thousand, one hundred thirty-three".