87778169 has 2 divisors, whose sum is σ = 87778170. Its totient is φ = 87778168.

The previous prime is 87778151. The next prime is 87778177. The reversal of 87778169 is 96187778.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87516025 + 262144 = 9355^2 + 512^2 .

It is a cyclic number.

It is not a de Polignac number, because 87778169 - 2²⁰ = 86729593 is a prime.

It is a super-2 number, since 2×87778169² = 15410013905985122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 87778169.

It is not a weakly prime, because it can be changed into another prime (87778109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43889084 + 43889085.

It is an arithmetic number, because the mean of its divisors is an integer number (43889085).

Almost surely, 2^87778169 is an apocalyptic number.

It is an amenable number.

87778169 is a deficient number, since it is larger than the sum of its proper divisors (1).

87778169 is an equidigital number, since it uses as much as digits as its factorization.

87778169 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 87778169 is about 9369.0004269399. Note that the first 3 decimals coincide. The cubic root of 87778169 is about 444.4219553459.

The spelling of 87778169 in words is "eighty-seven million, seven hundred seventy-eight thousand, one hundred sixty-nine".