661611105 has 32 divisors (see below), whose sum is σ = 1187867520. Its totient is φ = 349358400.

The previous prime is 661611091. The next prime is 661611161. The reversal of 661611105 is 501116166.

It is not a de Polignac number, because 661611105 - 2⁷ = 661610977 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10627 + ... + 37896.

It is an arithmetic number, because the mean of its divisors is an integer number (37120860).

Almost surely, 2^661611105 is an apocalyptic number.

It is an amenable number.

661611105 is a deficient number, since it is larger than the sum of its proper divisors (526256415).

661611105 is a wasteful number, since it uses less digits than its factorization.

661611105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48638 (or 48632 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 661611105 is about 25721.8021335986. The cubic root of 661611105 is about 871.3666392492.

The spelling of 661611105 in words is "six hundred sixty-one million, six hundred eleven thousand, one hundred five".