87790069 has 2 divisors, whose sum is σ = 87790070. Its totient is φ = 87790068.

The previous prime is 87790067. The next prime is 87790121. The reversal of 87790069 is 96009778.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72029169 + 15760900 = 8487^2 + 3970^2 .

It is a cyclic number.

It is not a de Polignac number, because 87790069 - 2¹ = 87790067 is a prime.

It is a super-2 number, since 2×87790069² = 15414192430049522, which contains 22 as substring.

Together with 87790067, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87790067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43895034 + 43895035.

It is an arithmetic number, because the mean of its divisors is an integer number (43895035).

Almost surely, 2^87790069 is an apocalyptic number.

It is an amenable number.

87790069 is a deficient number, since it is larger than the sum of its proper divisors (1).

87790069 is an equidigital number, since it uses as much as digits as its factorization.

87790069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 190512, while the sum is 46.

The square root of 87790069 is about 9369.6354785018. The cubic root of 87790069 is about 444.4420377208.

It can be divided in two parts, 877900 and 69, that added together give a square (877969 = 937²).

The spelling of 87790069 in words is "eighty-seven million, seven hundred ninety thousand, sixty-nine".