87678991 has 2 divisors, whose sum is σ = 87678992. Its totient is φ = 87678990.

The previous prime is 87678971. The next prime is 87679027. The reversal of 87678991 is 19987678.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87678991 - 2¹⁷ = 87547919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87678931) 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, 43839495 + 43839496.

It is an arithmetic number, because the mean of its divisors is an integer number (43839496).

Almost surely, 2^87678991 is an apocalyptic number.

87678991 is a deficient number, since it is larger than the sum of its proper divisors (1).

87678991 is an equidigital number, since it uses as much as digits as its factorization.

87678991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1524096, while the sum is 55.

The square root of 87678991 is about 9363.7060504909. The cubic root of 87678991 is about 444.2545124535.

The spelling of 87678991 in words is "eighty-seven million, six hundred seventy-eight thousand, nine hundred ninety-one".