84990991 has 8 divisors (see below), whose sum is σ = 87187968. Its totient is φ = 82800000.

The previous prime is 84990977. The next prime is 84991019. The reversal of 84990991 is 19909948.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 84990991 - 2¹⁹ = 84466703 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 (84990901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46291 + ... + 48091.

It is an arithmetic number, because the mean of its divisors is an integer number (10898496).

Almost surely, 2^84990991 is an apocalyptic number.

84990991 is a deficient number, since it is larger than the sum of its proper divisors (2196977).

84990991 is a wasteful number, since it uses less digits than its factorization.

84990991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2993.

The product of its (nonzero) digits is 209952, while the sum is 49.

The square root of 84990991 is about 9219.0558627226. The cubic root of 84990991 is about 439.6674329264.

The spelling of 84990991 in words is "eighty-four million, nine hundred ninety thousand, nine hundred ninety-one".