84531409 has 2 divisors, whose sum is σ = 84531410. Its totient is φ = 84531408.

The previous prime is 84531407. The next prime is 84531439. The reversal of 84531409 is 90413548.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57335184 + 27196225 = 7572^2 + 5215^2 .

It is a cyclic number.

It is not a de Polignac number, because 84531409 - 2¹ = 84531407 is a prime.

Together with 84531407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (84531401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42265704 + 42265705.

It is an arithmetic number, because the mean of its divisors is an integer number (42265705).

Almost surely, 2^84531409 is an apocalyptic number.

It is an amenable number.

84531409 is a deficient number, since it is larger than the sum of its proper divisors (1).

84531409 is an equidigital number, since it uses as much as digits as its factorization.

84531409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 84531409 is about 9194.0964210737. The cubic root of 84531409 is about 438.8735113296.

The spelling of 84531409 in words is "eighty-four million, five hundred thirty-one thousand, four hundred nine".