9998691 has 4 divisors (see below), whose sum is σ = 13331592. Its totient is φ = 6665792.

The previous prime is 9998689. The next prime is 9998699. The reversal of 9998691 is 1968999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1968999 = 3 ⋅656333.

It is a cyclic number.

It is not a de Polignac number, because 9998691 - 2¹ = 9998689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9998699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1666446 + ... + 1666451.

It is an arithmetic number, because the mean of its divisors is an integer number (3332898).

Almost surely, 2^9998691 is an apocalyptic number.

9998691 is a deficient number, since it is larger than the sum of its proper divisors (3332901).

9998691 is a wasteful number, since it uses less digits than its factorization.

9998691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3332900.

The product of its digits is 314928, while the sum is 51.

The square root of 9998691 is about 3162.0706823219. The cubic root of 9998691 is about 215.4340680763.

It can be divided in two parts, 99 and 98691, that added together give a triangular number (98790 = T₄₄₄).

The spelling of 9998691 in words is "nine million, nine hundred ninety-eight thousand, six hundred ninety-one".