90789878509 has 8 divisors (see below), whose sum is σ = 99053125920. Its totient is φ = 82528234800.

The previous prime is 90789878507. The next prime is 90789878519. The reversal of 90789878509 is 90587898709.

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

It is not a de Polignac number, because 90789878509 - 2¹ = 90789878507 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90789878503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 280987 + ... + 510424.

It is an arithmetic number, because the mean of its divisors is an integer number (12381640740).

Almost surely, 2^90789878509 is an apocalyptic number.

It is an amenable number.

90789878509 is a deficient number, since it is larger than the sum of its proper divisors (8263247411).

90789878509 is a wasteful number, since it uses less digits than its factorization.

90789878509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801851.

The product of its (nonzero) digits is 91445760, while the sum is 70.

The spelling of 90789878509 in words is "ninety billion, seven hundred eighty-nine million, eight hundred seventy-eight thousand, five hundred nine".