1009921 has 4 divisors (see below), whose sum is σ = 1101744. Its totient is φ = 918100.

The previous prime is 1009909. The next prime is 1009927. The reversal of 1009921 is 1299001.

1009921 = T₄₂₃ + T₄₂₄ + ... + T₄₃₃.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1009921 - 2¹¹ = 1007873 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1009892 and 1009901.

It is not an unprimeable number, because it can be changed into a prime (1009927) 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, 45895 + ... + 45916.

It is an arithmetic number, because the mean of its divisors is an integer number (275436).

2^1009921 is an apocalyptic number.

1009921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1009921 is a deficient number, since it is larger than the sum of its proper divisors (91823).

1009921 is an equidigital number, since it uses as much as digits as its factorization.

1009921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91822.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 1009921 is about 1004.9482573745. The cubic root of 1009921 is about 100.3296123632.

The spelling of 1009921 in words is "one million, nine thousand, nine hundred twenty-one".