661125201 has 16 divisors (see below), whose sum is σ = 965959680. Its totient is φ = 398880720.

The previous prime is 661125191. The next prime is 661125239. The reversal of 661125201 is 102521166.

It is not a de Polignac number, because 661125201 - 2⁵ = 661125169 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661125281) 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 15 ways as a sum of consecutive naturals, for example, 37561 + ... + 52278.

It is an arithmetic number, because the mean of its divisors is an integer number (60372480).

Almost surely, 2^661125201 is an apocalyptic number.

It is an amenable number.

661125201 is a deficient number, since it is larger than the sum of its proper divisors (304834479).

661125201 is a wasteful number, since it uses less digits than its factorization.

661125201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90076.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 661125201 is about 25712.3550263293. The cubic root of 661125201 is about 871.1532690752.

Adding to 661125201 its reverse (102521166), we get a palindrome (763646367).

The spelling of 661125201 in words is "six hundred sixty-one million, one hundred twenty-five thousand, two hundred one".