1661116078 has 16 divisors (see below), whose sum is σ = 2634282000. Its totient is φ = 783404352.

The previous prime is 1661116069. The next prime is 1661116091. The reversal of 1661116078 is 8706111661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 86743 + ... + 104146.

It is an arithmetic number, because the mean of its divisors is an integer number (164642625).

Almost surely, 2^1661116078 is an apocalyptic number.

1661116078 is a deficient number, since it is larger than the sum of its proper divisors (973165922).

1661116078 is a wasteful number, since it uses less digits than its factorization.

1661116078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191139.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 1661116078 is about 40756.7918021034. The cubic root of 1661116078 is about 1184.3134475504.

The spelling of 1661116078 in words is "one billion, six hundred sixty-one million, one hundred sixteen thousand, seventy-eight".