84390391 has 2 divisors, whose sum is σ = 84390392. Its totient is φ = 84390390.

The previous prime is 84390379. The next prime is 84390403. The reversal of 84390391 is 19309348.

It is a balanced prime because it is at equal distance from previous prime (84390379) and next prime (84390403).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84390391 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 84390391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84330391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42195195 + 42195196.

It is an arithmetic number, because the mean of its divisors is an integer number (42195196).

Almost surely, 2^84390391 is an apocalyptic number.

84390391 is a deficient number, since it is larger than the sum of its proper divisors (1).

84390391 is an equidigital number, since it uses as much as digits as its factorization.

84390391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 84390391 is about 9186.4242771603. The cubic root of 84390391 is about 438.6293278851.

The spelling of 84390391 in words is "eighty-four million, three hundred ninety thousand, three hundred ninety-one".