90709891 has 8 divisors (see below), whose sum is σ = 91625184. Its totient is φ = 89799360.

The previous prime is 90709889. The next prime is 90709921. The reversal of 90709891 is 19890709.

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 90709891 - 2¹ = 90709889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90709811) 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 7 ways as a sum of consecutive naturals, for example, 45961 + ... + 47893.

It is an arithmetic number, because the mean of its divisors is an integer number (11453148).

Almost surely, 2^90709891 is an apocalyptic number.

90709891 is a deficient number, since it is larger than the sum of its proper divisors (915293).

90709891 is a wasteful number, since it uses less digits than its factorization.

90709891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2381.

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 90709891 is about 9524.1740324293. The cubic root of 90709891 is about 449.3156527959.

The spelling of 90709891 in words is "ninety million, seven hundred nine thousand, eight hundred ninety-one".