9998909591 has 8 divisors (see below), whose sum is σ = 10950347664. Its totient is φ = 9054545920.

The previous prime is 9998909587. The next prime is 9998909597. The reversal of 9998909591 is 1959098999.

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 9998909591 - 2² = 9998909587 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 (9998909597) 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, 1765640 + ... + 1771293.

It is an arithmetic number, because the mean of its divisors is an integer number (1368793458).

Almost surely, 2^9998909591 is an apocalyptic number.

9998909591 is a deficient number, since it is larger than the sum of its proper divisors (951438073).

9998909591 is a wasteful number, since it uses less digits than its factorization.

9998909591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3537201.

The product of its (nonzero) digits is 21257640, while the sum is 68.

The square root of 9998909591 is about 99994.5478063679. The cubic root of 9998909591 is about 2154.3563800196.

The spelling of 9998909591 in words is "nine billion, nine hundred ninety-eight million, nine hundred nine thousand, five hundred ninety-one".