84742991 has 4 divisors (see below), whose sum is σ = 84843192. Its totient is φ = 84642792.

The previous prime is 84742979. The next prime is 84742993. The reversal of 84742991 is 19924748.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 84742991 - 2²² = 80548687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84742993) 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 in 3 ways as a sum of consecutive naturals, for example, 48821 + ... + 50526.

It is an arithmetic number, because the mean of its divisors is an integer number (21210798).

Almost surely, 2^84742991 is an apocalyptic number.

84742991 is a deficient number, since it is larger than the sum of its proper divisors (100201).

84742991 is an equidigital number, since it uses as much as digits as its factorization.

84742991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100200.

The product of its digits is 145152, while the sum is 44.

The square root of 84742991 is about 9205.5956352645. The cubic root of 84742991 is about 439.2393728465.

The spelling of 84742991 in words is "eighty-four million, seven hundred forty-two thousand, nine hundred ninety-one".