87187819 has 2 divisors, whose sum is σ = 87187820. Its totient is φ = 87187818.

The previous prime is 87187811. The next prime is 87187829. The reversal of 87187819 is 91878178.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87187819 - 2³ = 87187811 is a prime.

It is a super-2 number, since 2×87187819² = 15203431563953522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (87187811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43593909 + 43593910.

It is an arithmetic number, because the mean of its divisors is an integer number (43593910).

Almost surely, 2^87187819 is an apocalyptic number.

87187819 is a deficient number, since it is larger than the sum of its proper divisors (1).

87187819 is an equidigital number, since it uses as much as digits as its factorization.

87187819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 225792, while the sum is 49.

The square root of 87187819 is about 9337.4417802737. The cubic root of 87187819 is about 443.4233969446.

The spelling of 87187819 in words is "eighty-seven million, one hundred eighty-seven thousand, eight hundred nineteen".