82187509 has 2 divisors, whose sum is σ = 82187510. Its totient is φ = 82187508.

The previous prime is 82187489. The next prime is 82187543. The reversal of 82187509 is 90578128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79263409 + 2924100 = 8903^2 + 1710^2 .

It is a cyclic number.

It is not a de Polignac number, because 82187509 - 2⁵ = 82187477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82187569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41093754 + 41093755.

It is an arithmetic number, because the mean of its divisors is an integer number (41093755).

Almost surely, 2^82187509 is an apocalyptic number.

It is an amenable number.

82187509 is a deficient number, since it is larger than the sum of its proper divisors (1).

82187509 is an equidigital number, since it uses as much as digits as its factorization.

82187509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 82187509 is about 9065.7326786090. The cubic root of 82187509 is about 434.7790466379.

The spelling of 82187509 in words is "eighty-two million, one hundred eighty-seven thousand, five hundred nine".