9991869 has 8 divisors (see below), whose sum is σ = 14106240. Its totient is φ = 6269376.

The previous prime is 9991847. The next prime is 9991879. The reversal of 9991869 is 9681999.

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

It is not a de Polignac number, because 9991869 - 2⁵ = 9991837 is a prime.

It is a super-2 number, since 2×9991869² = 199674892226322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51), and also a Moran number because the ratio is a prime number: 195919 = 9991869 / (9 + 9 + 9 + 1 + 8 + 6 + 9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9991879) 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, 97909 + ... + 98010.

It is an arithmetic number, because the mean of its divisors is an integer number (1763280).

Almost surely, 2^9991869 is an apocalyptic number.

It is an amenable number.

9991869 is a deficient number, since it is larger than the sum of its proper divisors (4114371).

9991869 is a wasteful number, since it uses less digits than its factorization.

9991869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195939.

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

The square root of 9991869 is about 3160.9917747441. The cubic root of 9991869 is about 215.3850608082.

The spelling of 9991869 in words is "nine million, nine hundred ninety-one thousand, eight hundred sixty-nine".