78876521 has 2 divisors, whose sum is σ = 78876522. Its totient is φ = 78876520.

The previous prime is 78876509. The next prime is 78876533. The reversal of 78876521 is 12567887.

It is a balanced prime because it is at equal distance from previous prime (78876509) and next prime (78876533).

It can be written as a sum of positive squares in only one way, i.e., 48846121 + 30030400 = 6989^2 + 5480^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78876521 is a prime.

It is not a weakly prime, because it can be changed into another prime (78876571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39438260 + 39438261.

It is an arithmetic number, because the mean of its divisors is an integer number (39438261).

Almost surely, 2^78876521 is an apocalyptic number.

It is an amenable number.

78876521 is a deficient number, since it is larger than the sum of its proper divisors (1).

78876521 is an equidigital number, since it uses as much as digits as its factorization.

78876521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 188160, while the sum is 44.

The square root of 78876521 is about 8881.2454644605. The cubic root of 78876521 is about 428.8603697194.

It can be divided in two parts, 78876 and 521, that added together give a palindrome (79397).

The spelling of 78876521 in words is "seventy-eight million, eight hundred seventy-six thousand, five hundred twenty-one".