78235645 has 4 divisors (see below), whose sum is σ = 93882780. Its totient is φ = 62588512.

The previous prime is 78235643. The next prime is 78235657. The reversal of 78235645 is 54653287.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43731769 + 34503876 = 6613^2 + 5874^2 .

It is a cyclic number.

It is not a de Polignac number, because 78235645 - 2¹ = 78235643 is a prime.

It is a super-2 number, since 2×78235645² = 12241632297132050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 78235598 and 78235607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78235643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7823560 + ... + 7823569.

It is an arithmetic number, because the mean of its divisors is an integer number (23470695).

Almost surely, 2^78235645 is an apocalyptic number.

It is an amenable number.

78235645 is a deficient number, since it is larger than the sum of its proper divisors (15647135).

78235645 is a wasteful number, since it uses less digits than its factorization.

78235645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15647134.

The product of its digits is 201600, while the sum is 40.

The square root of 78235645 is about 8845.0915766882. The cubic root of 78235645 is about 427.6957051120.

The spelling of 78235645 in words is "seventy-eight million, two hundred thirty-five thousand, six hundred forty-five".