84409861 has 2 divisors, whose sum is σ = 84409862. Its totient is φ = 84409860.

The previous prime is 84409847. The next prime is 84409877. The reversal of 84409861 is 16890448.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79032100 + 5377761 = 8890^2 + 2319^2 .

It is a cyclic number.

It is not a de Polignac number, because 84409861 - 2¹⁹ = 83885573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84409891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42204930 + 42204931.

It is an arithmetic number, because the mean of its divisors is an integer number (42204931).

Almost surely, 2^84409861 is an apocalyptic number.

It is an amenable number.

84409861 is a deficient number, since it is larger than the sum of its proper divisors (1).

84409861 is an equidigital number, since it uses as much as digits as its factorization.

84409861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 84409861 is about 9187.4839319587. The cubic root of 84409861 is about 438.6630578561.

The spelling of 84409861 in words is "eighty-four million, four hundred nine thousand, eight hundred sixty-one".