84131921 has 2 divisors, whose sum is σ = 84131922. Its totient is φ = 84131920.

The previous prime is 84131909. The next prime is 84131933. The reversal of 84131921 is 12913148.

It is a balanced prime because it is at equal distance from previous prime (84131909) and next prime (84131933).

It can be written as a sum of positive squares in only one way, i.e., 50908225 + 33223696 = 7135^2 + 5764^2 .

It is a cyclic number.

It is not a de Polignac number, because 84131921 - 2⁶ = 84131857 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (84131321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42065960 + 42065961.

It is an arithmetic number, because the mean of its divisors is an integer number (42065961).

Almost surely, 2^84131921 is an apocalyptic number.

It is an amenable number.

84131921 is a deficient number, since it is larger than the sum of its proper divisors (1).

84131921 is an equidigital number, since it uses as much as digits as its factorization.

84131921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 29.

The square root of 84131921 is about 9172.3454470490. The cubic root of 84131921 is about 438.1810601626.

The spelling of 84131921 in words is "eighty-four million, one hundred thirty-one thousand, nine hundred twenty-one".