87091019 has 2 divisors, whose sum is σ = 87091020. Its totient is φ = 87091018.

The previous prime is 87091013. The next prime is 87091061. The reversal of 87091019 is 91019078.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87091019 - 2¹⁶ = 87025483 is a prime.

It is a super-2 number, since 2×87091019² = 15169691180916722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 87091019.

It is not a weakly prime, because it can be changed into another prime (87091013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43545509 + 43545510.

It is an arithmetic number, because the mean of its divisors is an integer number (43545510).

Almost surely, 2^87091019 is an apocalyptic number.

87091019 is a deficient number, since it is larger than the sum of its proper divisors (1).

87091019 is an equidigital number, since it uses as much as digits as its factorization.

87091019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 35.

The square root of 87091019 is about 9332.2569081654. The cubic root of 87091019 is about 443.2592330346.

The spelling of 87091019 in words is "eighty-seven million, ninety-one thousand, nineteen".