84209491 has 2 divisors, whose sum is σ = 84209492. Its totient is φ = 84209490.

The previous prime is 84209473. The next prime is 84209507. The reversal of 84209491 is 19490248.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 84209491 - 2⁵ = 84209459 is a prime.

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 84209491.

It is not a weakly prime, because it can be changed into another prime (84209431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42104745 + 42104746.

It is an arithmetic number, because the mean of its divisors is an integer number (42104746).

Almost surely, 2^84209491 is an apocalyptic number.

84209491 is a deficient number, since it is larger than the sum of its proper divisors (1).

84209491 is an equidigital number, since it uses as much as digits as its factorization.

84209491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 84209491 is about 9176.5729441878. The cubic root of 84209491 is about 438.3156870817.

The spelling of 84209491 in words is "eighty-four million, two hundred nine thousand, four hundred ninety-one".