84405491 has 4 divisors (see below), whose sum is σ = 84423912. Its totient is φ = 84387072.

The previous prime is 84405487. The next prime is 84405499. The reversal of 84405491 is 19450448.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 84405491 - 2² = 84405487 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84405499) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3635 + ... + 13491.

It is an arithmetic number, because the mean of its divisors is an integer number (21105978).

Almost surely, 2^84405491 is an apocalyptic number.

84405491 is a deficient number, since it is larger than the sum of its proper divisors (18421).

84405491 is an equidigital number, since it uses as much as digits as its factorization.

84405491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18420.

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 84405491 is about 9187.2461053354. The cubic root of 84405491 is about 438.6554876874.

It can be divided in two parts, 8440 and 5491, that added together give a palindrome (13931).

The spelling of 84405491 in words is "eighty-four million, four hundred five thousand, four hundred ninety-one".