78528917 has 2 divisors, whose sum is σ = 78528918. Its totient is φ = 78528916.

The previous prime is 78528913. The next prime is 78528937. The reversal of 78528917 is 71982587.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69372241 + 9156676 = 8329^2 + 3026^2 .

It is a cyclic number.

It is not a de Polignac number, because 78528917 - 2² = 78528913 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78528913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39264458 + 39264459.

It is an arithmetic number, because the mean of its divisors is an integer number (39264459).

Almost surely, 2^78528917 is an apocalyptic number.

It is an amenable number.

78528917 is a deficient number, since it is larger than the sum of its proper divisors (1).

78528917 is an equidigital number, since it uses as much as digits as its factorization.

78528917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 282240, while the sum is 47.

The square root of 78528917 is about 8861.6543037968. The cubic root of 78528917 is about 428.2294548758.

The spelling of 78528917 in words is "seventy-eight million, five hundred twenty-eight thousand, nine hundred seventeen".