661165078 has 32 divisors (see below), whose sum is σ = 1195084800. Its totient is φ = 267992064.

The previous prime is 661165073. The next prime is 661165081. The reversal of 661165078 is 870561166.

It is a self number, because there is not a number n which added to its sum of digits gives 661165078.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661165073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 189526 + ... + 192982.

It is an arithmetic number, because the mean of its divisors is an integer number (37346400).

Almost surely, 2^661165078 is an apocalyptic number.

661165078 is a deficient number, since it is larger than the sum of its proper divisors (533919722).

661165078 is a wasteful number, since it uses less digits than its factorization.

661165078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4204.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 661165078 is about 25713.1304589698. The cubic root of 661165078 is about 871.1707838013.

The spelling of 661165078 in words is "six hundred sixty-one million, one hundred sixty-five thousand, seventy-eight".