78053665 has 4 divisors (see below), whose sum is σ = 93664404. Its totient is φ = 62442928.

The previous prime is 78053663. The next prime is 78053671. The reversal of 78053665 is 56635087.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56635087 = 223 ⋅253969.

It can be written as a sum of positive squares in 2 ways, for example, as 9296401 + 68757264 = 3049^2 + 8292^2 .

It is a cyclic number.

It is not a de Polignac number, because 78053665 - 2¹ = 78053663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78053663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7805362 + ... + 7805371.

It is an arithmetic number, because the mean of its divisors is an integer number (23416101).

Almost surely, 2^78053665 is an apocalyptic number.

It is an amenable number.

78053665 is a deficient number, since it is larger than the sum of its proper divisors (15610739).

78053665 is a wasteful number, since it uses less digits than its factorization.

78053665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15610738.

The product of its (nonzero) digits is 151200, while the sum is 40.

The square root of 78053665 is about 8834.7985262823. The cubic root of 78053665 is about 427.3638338377.

It can be divided in two parts, 780 and 53665, that added together give a palindrome (54445).

The spelling of 78053665 in words is "seventy-eight million, fifty-three thousand, six hundred sixty-five".