9921887 has 4 divisors (see below), whose sum is σ = 10018320. Its totient is φ = 9825456.

The previous prime is 9921869. The next prime is 9921889. The reversal of 9921887 is 7881299.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 9921887 - 2⁶ = 9921823 is a prime.

It is a super-3 number, since 3×9921887³ (a number of 22 digits) contains 333 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9921889) 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, 48062 + ... + 48267.

It is an arithmetic number, because the mean of its divisors is an integer number (2504580).

Almost surely, 2^9921887 is an apocalyptic number.

9921887 is a deficient number, since it is larger than the sum of its proper divisors (96433).

9921887 is a wasteful number, since it uses less digits than its factorization.

9921887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96432.

The product of its digits is 72576, while the sum is 44.

The square root of 9921887 is about 3149.9026969099. The cubic root of 9921887 is about 214.8810374876.

The spelling of 9921887 in words is "nine million, nine hundred twenty-one thousand, eight hundred eighty-seven".