78661332 has 18 divisors (see below), whose sum is σ = 198838458. Its totient is φ = 26220432.

The previous prime is 78661321. The next prime is 78661339. The reversal of 78661332 is 23316687.

It is a happy number.

78661332 is a `hidden beast` number, since 7 + 8 + 6 + 613 + 32 = 666.

It can be written as a sum of positive squares in only one way, i.e., 65221776 + 13439556 = 8076^2 + 3666^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 2185037 = 78661332 / (7 + 8 + 6 + 6 + 1 + 3 + 3 + 2).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78661339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1092483 + ... + 1092554.

It is an arithmetic number, because the mean of its divisors is an integer number (11046581).

Almost surely, 2^78661332 is an apocalyptic number.

It is an amenable number.

78661332 is an abundant number, since it is smaller than the sum of its proper divisors (120177126).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78661332 is a wasteful number, since it uses less digits than its factorization.

78661332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2185047 (or 2185042 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 78661332 is about 8869.1223917590. The cubic root of 78661332 is about 428.4700123839.

The spelling of 78661332 in words is "seventy-eight million, six hundred sixty-one thousand, three hundred thirty-two".