82420409 has 2 divisors, whose sum is σ = 82420410. Its totient is φ = 82420408.

The previous prime is 82420399. The next prime is 82420417. The reversal of 82420409 is 90402428.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80048809 + 2371600 = 8947^2 + 1540^2 .

It is a cyclic number.

It is not a de Polignac number, because 82420409 - 2²⁰ = 81371833 is a prime.

It is equal to p_4802429 and since 82420409 and 4802429 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (82420439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41210204 + 41210205.

It is an arithmetic number, because the mean of its divisors is an integer number (41210205).

Almost surely, 2^82420409 is an apocalyptic number.

It is an amenable number.

82420409 is a deficient number, since it is larger than the sum of its proper divisors (1).

82420409 is an equidigital number, since it uses as much as digits as its factorization.

82420409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 82420409 is about 9078.5686647180. The cubic root of 82420409 is about 435.1893463800.

The spelling of 82420409 in words is "eighty-two million, four hundred twenty thousand, four hundred nine".