78521675 has 12 divisors (see below), whose sum is σ = 97504176. Its totient is φ = 62728800.

The previous prime is 78521671. The next prime is 78521689. The reversal of 78521675 is 57612587.

It is not a de Polignac number, because 78521675 - 2² = 78521671 is a prime.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78521671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20405 + ... + 23945.

It is an arithmetic number, because the mean of its divisors is an integer number (8125348).

Almost surely, 2^78521675 is an apocalyptic number.

78521675 is a deficient number, since it is larger than the sum of its proper divisors (18982501).

78521675 is a wasteful number, since it uses less digits than its factorization.

78521675 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4438 (or 4433 counting only the distinct ones).

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

The square root of 78521675 is about 8861.2456799256. The cubic root of 78521675 is about 428.2162905827.

The spelling of 78521675 in words is "seventy-eight million, five hundred twenty-one thousand, six hundred seventy-five".