78428677 has 2 divisors, whose sum is σ = 78428678. Its totient is φ = 78428676.

The previous prime is 78428627. The next prime is 78428699. The reversal of 78428677 is 77682487.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51065316 + 27363361 = 7146^2 + 5231^2 .

It is an emirp because it is prime and its reverse (77682487) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78428677 - 2⁷ = 78428549 is a prime.

It is a super-3 number, since 3×78428677³ (a number of 25 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78428677.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78428617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39214338 + 39214339.

It is an arithmetic number, because the mean of its divisors is an integer number (39214339).

Almost surely, 2^78428677 is an apocalyptic number.

It is an amenable number.

78428677 is a deficient number, since it is larger than the sum of its proper divisors (1).

78428677 is an equidigital number, since it uses as much as digits as its factorization.

78428677 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1053696, while the sum is 49.

The square root of 78428677 is about 8855.9966689244. The cubic root of 78428677 is about 428.0471695909.

The spelling of 78428677 in words is "seventy-eight million, four hundred twenty-eight thousand, six hundred seventy-seven".