78778725 has 24 divisors (see below), whose sum is σ = 130503552. Its totient is φ = 41932800.

The previous prime is 78778669. The next prime is 78778787. The reversal of 78778725 is 52787787.

It is not a de Polignac number, because 78778725 - 2⁷ = 78778597 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 67749 + ... + 68901.

It is an arithmetic number, because the mean of its divisors is an integer number (5437648).

Almost surely, 2^78778725 is an apocalyptic number.

78778725 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

It is an amenable number.

78778725 is a deficient number, since it is larger than the sum of its proper divisors (51724827).

78778725 is a wasteful number, since it uses less digits than its factorization.

78778725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2077 (or 2072 counting only the distinct ones).

The product of its digits is 1536640, while the sum is 51.

The square root of 78778725 is about 8875.7379974851. The cubic root of 78778725 is about 428.6830538602.

The spelling of 78778725 in words is "seventy-eight million, seven hundred seventy-eight thousand, seven hundred twenty-five".