87989819 has 2 divisors, whose sum is σ = 87989820. Its totient is φ = 87989818.

The previous prime is 87989809. The next prime is 87989821. The reversal of 87989819 is 91898978.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87989819 is a prime.

It is a super-2 number, since 2×87989819² = 15484416495305522, which contains 22 as substring.

Together with 87989821, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (87989809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43994909 + 43994910.

It is an arithmetic number, because the mean of its divisors is an integer number (43994910).

Almost surely, 2^87989819 is an apocalyptic number.

87989819 is a deficient number, since it is larger than the sum of its proper divisors (1).

87989819 is an equidigital number, since it uses as much as digits as its factorization.

87989819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2612736, while the sum is 59.

The square root of 87989819 is about 9380.2888548274. The cubic root of 87989819 is about 444.7788641634.

The spelling of 87989819 in words is "eighty-seven million, nine hundred eighty-nine thousand, eight hundred nineteen".