78661101 has 16 divisors (see below), whose sum is σ = 106989120. Its totient is φ = 51392640.

The previous prime is 78661087. The next prime is 78661103. The reversal of 78661101 is 10116687.

It is a happy number.

It is not a de Polignac number, because 78661101 - 2⁷ = 78660973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78661103) 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, 91791 + ... + 92643.

It is an arithmetic number, because the mean of its divisors is an integer number (6686820).

Almost surely, 2^78661101 is an apocalyptic number.

It is an amenable number.

78661101 is a deficient number, since it is larger than the sum of its proper divisors (28328019).

78661101 is a wasteful number, since it uses less digits than its factorization.

78661101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1436.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 78661101 is about 8869.1093690404. The cubic root of 78661101 is about 428.4695929628.

Adding to 78661101 its reverse (10116687), we get a palindrome (88777788).

The spelling of 78661101 in words is "seventy-eight million, six hundred sixty-one thousand, one hundred one".