661862205 has 32 divisors (see below), whose sum is σ = 1179619200. Its totient is φ = 352100736.

The previous prime is 661862167. The next prime is 661862209. The reversal of 661862205 is 502268166.

It is not a de Polignac number, because 661862205 - 2¹⁵ = 661829437 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 661862205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661862209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49222 + ... + 61208.

It is an arithmetic number, because the mean of its divisors is an integer number (36863100).

Almost surely, 2^661862205 is an apocalyptic number.

It is an amenable number.

661862205 is a deficient number, since it is larger than the sum of its proper divisors (517756995).

661862205 is a wasteful number, since it uses less digits than its factorization.

661862205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12410 (or 12404 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 661862205 is about 25726.6827437973. The cubic root of 661862205 is about 871.4768613454.

The spelling of 661862205 in words is "six hundred sixty-one million, eight hundred sixty-two thousand, two hundred five".