84665639 has 2 divisors, whose sum is σ = 84665640. Its totient is φ = 84665638.

The previous prime is 84665579. The next prime is 84665677. The reversal of 84665639 is 93656648.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84665639 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 84665593 and 84665602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84661639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42332819 + 42332820.

It is an arithmetic number, because the mean of its divisors is an integer number (42332820).

Almost surely, 2^84665639 is an apocalyptic number.

84665639 is a deficient number, since it is larger than the sum of its proper divisors (1).

84665639 is an equidigital number, since it uses as much as digits as its factorization.

84665639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 933120, while the sum is 47.

The square root of 84665639 is about 9201.3933184056. The cubic root of 84665639 is about 439.1056886861.

The spelling of 84665639 in words is "eighty-four million, six hundred sixty-five thousand, six hundred thirty-nine".