9940821 has 8 divisors (see below), whose sum is σ = 14459424. Its totient is φ = 6024720.

The previous prime is 9940813. The next prime is 9940831. The reversal of 9940821 is 1280499.

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

It is not a de Polignac number, because 9940821 - 2³ = 9940813 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 301237 = 9940821 / (9 + 9 + 4 + 0 + 8 + 2 + 1).

9940821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9940811) 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, 150586 + ... + 150651.

It is an arithmetic number, because the mean of its divisors is an integer number (1807428).

Almost surely, 2^9940821 is an apocalyptic number.

It is an amenable number.

9940821 is a deficient number, since it is larger than the sum of its proper divisors (4518603).

9940821 is a wasteful number, since it uses less digits than its factorization.

9940821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301251.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 9940821 is about 3152.9067540922. The cubic root of 9940821 is about 215.0176369162.

The spelling of 9940821 in words is "nine million, nine hundred forty thousand, eight hundred twenty-one".