661111858 has 32 divisors (see below), whose sum is σ = 1094430528. Its totient is φ = 297024000.

The previous prime is 661111837. The next prime is 661111883. The reversal of 661111858 is 858111166.

661111858 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1208341 + ... + 1208887.

It is an arithmetic number, because the mean of its divisors is an integer number (34200954).

Almost surely, 2^661111858 is an apocalyptic number.

661111858 is a deficient number, since it is larger than the sum of its proper divisors (433318670).

661111858 is a wasteful number, since it uses less digits than its factorization.

661111858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1098.

The product of its digits is 11520, while the sum is 37.

The square root of 661111858 is about 25712.0955583165. The cubic root of 661111858 is about 871.1474084221.

The spelling of 661111858 in words is "six hundred sixty-one million, one hundred eleven thousand, eight hundred fifty-eight".