661100625 has 30 divisors (see below), whose sum is σ = 1193282090. Its totient is φ = 352584000.

The previous prime is 661100623. The next prime is 661100653. The reversal of 661100625 is 526001166.

It is a happy number.

661100625 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 5 ways, for example, as 242611776 + 418488849 = 15576^2 + 20457^2 .

It is not a de Polignac number, because 661100625 - 2¹ = 661100623 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661100623) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 53140 + ... + 64389.

Almost surely, 2^661100625 is an apocalyptic number.

It is an amenable number.

661100625 is a deficient number, since it is larger than the sum of its proper divisors (532181465).

661100625 is a wasteful number, since it uses less digits than its factorization.

661100625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117555 (or 117537 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 661100625 is about 25711.8771193392. The cubic root of 661100625 is about 871.1424744844.

The spelling of 661100625 in words is "six hundred sixty-one million, one hundred thousand, six hundred twenty-five".