78987577 has 2 divisors, whose sum is σ = 78987578. Its totient is φ = 78987576.

The previous prime is 78987569. The next prime is 78987581. The reversal of 78987577 is 77578987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73770921 + 5216656 = 8589^2 + 2284^2 .

It is an emirp because it is prime and its reverse (77578987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78987577 - 2³ = 78987569 is a prime.

It is not a weakly prime, because it can be changed into another prime (78987527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39493788 + 39493789.

It is an arithmetic number, because the mean of its divisors is an integer number (39493789).

Almost surely, 2^78987577 is an apocalyptic number.

It is an amenable number.

78987577 is a deficient number, since it is larger than the sum of its proper divisors (1).

78987577 is an equidigital number, since it uses as much as digits as its factorization.

78987577 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6914880, while the sum is 58.

The square root of 78987577 is about 8887.4955414897. The cubic root of 78987577 is about 429.0615499157.

The spelling of 78987577 in words is "seventy-eight million, nine hundred eighty-seven thousand, five hundred seventy-seven".