78521345 has 8 divisors (see below), whose sum is σ = 107686464. Its totient is φ = 53843184.

The previous prime is 78521341. The next prime is 78521347. The reversal of 78521345 is 54312587.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78521345 - 2² = 78521341 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35), and also a Moran number because the ratio is a prime number: 2243467 = 78521345 / (7 + 8 + 5 + 2 + 1 + 3 + 4 + 5).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78521341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1121699 + ... + 1121768.

It is an arithmetic number, because the mean of its divisors is an integer number (13460808).

Almost surely, 2^78521345 is an apocalyptic number.

It is an amenable number.

78521345 is a deficient number, since it is larger than the sum of its proper divisors (29165119).

78521345 is a wasteful number, since it uses less digits than its factorization.

78521345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2243479.

The product of its digits is 33600, while the sum is 35.

The square root of 78521345 is about 8861.2270594992. The cubic root of 78521345 is about 428.2156906992.

The spelling of 78521345 in words is "seventy-eight million, five hundred twenty-one thousand, three hundred forty-five".