84091831 has 2 divisors, whose sum is σ = 84091832. Its totient is φ = 84091830.

The previous prime is 84091829. The next prime is 84091849. The reversal of 84091831 is 13819048.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 84091831 - 2¹ = 84091829 is a prime.

It is a super-2 number, since 2×84091831² = 14142872081865122, which contains 22 as substring.

Together with 84091829, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84091031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42045915 + 42045916.

It is an arithmetic number, because the mean of its divisors is an integer number (42045916).

Almost surely, 2^84091831 is an apocalyptic number.

84091831 is a deficient number, since it is larger than the sum of its proper divisors (1).

84091831 is an equidigital number, since it uses as much as digits as its factorization.

84091831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 84091831 is about 9170.1598132203. The cubic root of 84091831 is about 438.1114493677. Note that the first 3 decimals are identical.

The spelling of 84091831 in words is "eighty-four million, ninety-one thousand, eight hundred thirty-one".