661560625 has 40 divisors (see below), whose sum is σ = 924229152. Its totient is φ = 469200000.

The previous prime is 661560623. The next prime is 661560643. The reversal of 661560625 is 526065166.

It is not a de Polignac number, because 661560625 - 2¹ = 661560623 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661560623) 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 39 ways as a sum of consecutive naturals, for example, 280702 + ... + 283048.

Almost surely, 2^661560625 is an apocalyptic number.

It is an amenable number.

661560625 is a deficient number, since it is larger than the sum of its proper divisors (262668527).

661560625 is a wasteful number, since it uses less digits than its factorization.

661560625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2419 (or 2404 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 661560625 is about 25720.8208461550. The cubic root of 661560625 is about 871.3444773344.

The spelling of 661560625 in words is "six hundred sixty-one million, five hundred sixty thousand, six hundred twenty-five".