10821721 has 8 divisors (see below), whose sum is σ = 11088000. Its totient is φ = 10558320.

The previous prime is 10821719. The next prime is 10821757. The reversal of 10821721 is 12712801.

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

It is a cyclic number.

It is not a de Polignac number, because 10821721 - 2¹ = 10821719 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10821692 and 10821701.

It is not an unprimeable number, because it can be changed into a prime (10821761) 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, 8176 + ... + 9406.

It is an arithmetic number, because the mean of its divisors is an integer number (1386000).

Almost surely, 2^10821721 is an apocalyptic number.

It is an amenable number.

10821721 is a deficient number, since it is larger than the sum of its proper divisors (266279).

10821721 is a wasteful number, since it uses less digits than its factorization.

10821721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1439.

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 10821721 is about 3289.6384299798. The cubic root of 10821721 is about 221.1899774406.

The spelling of 10821721 in words is "ten million, eight hundred twenty-one thousand, seven hundred twenty-one".