91020308989 has 8 divisors (see below), whose sum is σ = 92745639360. Its totient is φ = 89310592800.

The previous prime is 91020308983. The next prime is 91020309019. The reversal of 91020308989 is 98980302019.

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 91020308989 - 2¹¹ = 91020306941 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 (91020308983) 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, 3891777 + ... + 3915094.

It is an arithmetic number, because the mean of its divisors is an integer number (11593204920).

Almost surely, 2^91020308989 is an apocalyptic number.

It is an amenable number.

91020308989 is a deficient number, since it is larger than the sum of its proper divisors (1725330371).

91020308989 is a wasteful number, since it uses less digits than its factorization.

91020308989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7807091.

The product of its (nonzero) digits is 279936, while the sum is 49.

The spelling of 91020308989 in words is "ninety-one billion, twenty million, three hundred eight thousand, nine hundred eighty-nine".