78189677 has 2 divisors, whose sum is σ = 78189678. Its totient is φ = 78189676.

The previous prime is 78189649. The next prime is 78189689. The reversal of 78189677 is 77698187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59691076 + 18498601 = 7726^2 + 4301^2 .

It is a cyclic number.

It is not a de Polignac number, because 78189677 - 2⁸ = 78189421 is a prime.

It is a super-2 number, since 2×78189677² = 12227251178728658, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78189607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39094838 + 39094839.

It is an arithmetic number, because the mean of its divisors is an integer number (39094839).

Almost surely, 2^78189677 is an apocalyptic number.

It is an amenable number.

78189677 is a deficient number, since it is larger than the sum of its proper divisors (1).

78189677 is an equidigital number, since it uses as much as digits as its factorization.

78189677 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1185408, while the sum is 53.

The square root of 78189677 is about 8842.4926915435. The cubic root of 78189677 is about 427.6119233185.

The spelling of 78189677 in words is "seventy-eight million, one hundred eighty-nine thousand, six hundred seventy-seven".