661654111 has 16 divisors (see below), whose sum is σ = 709367040. Its totient is φ = 615767040.

The previous prime is 661654057. The next prime is 661654139. The reversal of 661654111 is 111456166.

661654111 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 661654111 - 2⁷ = 661653983 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661654711) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 247695 + ... + 250351.

It is an arithmetic number, because the mean of its divisors is an integer number (44335440).

Almost surely, 2^661654111 is an apocalyptic number.

661654111 is a deficient number, since it is larger than the sum of its proper divisors (47712929).

661654111 is a wasteful number, since it uses less digits than its factorization.

661654111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2994.

The product of its digits is 4320, while the sum is 31.

The square root of 661654111 is about 25722.6381034294. The cubic root of 661654111 is about 871.3855190118.

The spelling of 661654111 in words is "six hundred sixty-one million, six hundred fifty-four thousand, one hundred eleven".