78021992 has 16 divisors (see below), whose sum is σ = 148055040. Its totient is φ = 38540656.

The previous prime is 78021991. The next prime is 78021997. The reversal of 78021992 is 29912087.

It is not an unprimeable number, because it can be changed into a prime (78021991) 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 3 ways as a sum of consecutive naturals, for example, 58088 + ... + 59415.

It is an arithmetic number, because the mean of its divisors is an integer number (9253440).

Almost surely, 2^78021992 is an apocalyptic number.

It is an amenable number.

78021992 is a deficient number, since it is larger than the sum of its proper divisors (70033048).

78021992 is a wasteful number, since it uses less digits than its factorization.

78021992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117592 (or 117588 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 78021992 is about 8833.0058304068. The cubic root of 78021992 is about 427.3060200844.

The spelling of 78021992 in words is "seventy-eight million, twenty-one thousand, nine hundred ninety-two".