78125765 has 4 divisors (see below), whose sum is σ = 93750924. Its totient is φ = 62500608.

The previous prime is 78125753. The next prime is 78125767. The reversal of 78125765 is 56752187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56752187 = 3851 ⋅14737.

It can be written as a sum of positive squares in 2 ways, for example, as 9947716 + 68178049 = 3154^2 + 8257^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78125765 is a prime.

It is a super-2 number, since 2×78125765² = 12207270313670450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78125767) 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, 7812572 + ... + 7812581.

It is an arithmetic number, because the mean of its divisors is an integer number (23437731).

Almost surely, 2^78125765 is an apocalyptic number.

It is an amenable number.

78125765 is a deficient number, since it is larger than the sum of its proper divisors (15625159).

78125765 is a wasteful number, since it uses less digits than its factorization.

78125765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15625158.

The product of its digits is 117600, while the sum is 41.

The square root of 78125765 is about 8838.8780396609. The cubic root of 78125765 is about 427.4953820050.

The spelling of 78125765 in words is "seventy-eight million, one hundred twenty-five thousand, seven hundred sixty-five".