661605110 has 16 divisors (see below), whose sum is σ = 1219936032. Its totient is φ = 258187200.

The previous prime is 661605107. The next prime is 661605149. The reversal of 661605110 is 11506166.

It is a super-2 number, since 2×661605110² = 875442643156224200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 661605110.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 806426 + ... + 807245.

It is an arithmetic number, because the mean of its divisors is an integer number (76246002).

Almost surely, 2^661605110 is an apocalyptic number.

661605110 is a deficient number, since it is larger than the sum of its proper divisors (558330922).

661605110 is a wasteful number, since it uses less digits than its factorization.

661605110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1613719.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 661605110 is about 25721.6855979541. The cubic root of 661605110 is about 871.3640073613.

The spelling of 661605110 in words is "six hundred sixty-one million, six hundred five thousand, one hundred ten".