78785840 has 40 divisors (see below), whose sum is σ = 209346720. Its totient is φ = 27012096.

The previous prime is 78785821. The next prime is 78785843. The reversal of 78785840 is 4858787.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (78785843) 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 7 ways as a sum of consecutive naturals, for example, 69785 + ... + 70904.

It is an arithmetic number, because the mean of its divisors is an integer number (5233668).

Almost surely, 2^78785840 is an apocalyptic number.

78785840 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

78785840 is an abundant number, since it is smaller than the sum of its proper divisors (130560880).

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

78785840 is a wasteful number, since it uses less digits than its factorization.

78785840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140709 (or 140703 counting only the distinct ones).

The product of its (nonzero) digits is 501760, while the sum is 47.

The square root of 78785840 is about 8876.1388001766. The cubic root of 78785840 is about 428.6959591554.

The spelling of 78785840 in words is "seventy-eight million, seven hundred eighty-five thousand, eight hundred forty".