84391919 has 2 divisors, whose sum is σ = 84391920. Its totient is φ = 84391918.

The previous prime is 84391913. The next prime is 84391921. The reversal of 84391919 is 91919348.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84391919 is a prime.

It is a super-2 number, since 2×84391919² = 14243991985005122, which contains 22 as substring.

Together with 84391921, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 84391919.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84391913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42195959 + 42195960.

It is an arithmetic number, because the mean of its divisors is an integer number (42195960).

Almost surely, 2^84391919 is an apocalyptic number.

84391919 is a deficient number, since it is larger than the sum of its proper divisors (1).

84391919 is an equidigital number, since it uses as much as digits as its factorization.

84391919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 44.

The square root of 84391919 is about 9186.5074429840. The cubic root of 84391919 is about 438.6319751911.

The spelling of 84391919 in words is "eighty-four million, three hundred ninety-one thousand, nine hundred nineteen".