78521229 has 24 divisors (see below), whose sum is σ = 115577280. Its totient is φ = 51361728.

The previous prime is 78521227. The next prime is 78521293. The reversal of 78521229 is 92212587.

It is not a de Polignac number, because 78521229 - 2¹ = 78521227 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78521193 and 78521202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78521227) 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 23 ways as a sum of consecutive naturals, for example, 133474 + ... + 134060.

It is an arithmetic number, because the mean of its divisors is an integer number (4815720).

Almost surely, 2^78521229 is an apocalyptic number.

It is an amenable number.

78521229 is a deficient number, since it is larger than the sum of its proper divisors (37056051).

78521229 is a wasteful number, since it uses less digits than its factorization.

78521229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 849 (or 846 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 78521229 is about 8861.2205141278. The cubic root of 78521229 is about 428.2154798306.

The spelling of 78521229 in words is "seventy-eight million, five hundred twenty-one thousand, two hundred twenty-nine".