10213921 has 4 divisors (see below), whose sum is σ = 10221844. Its totient is φ = 10206000.

The previous prime is 10213891. The next prime is 10213927. The reversal of 10213921 is 12931201.

10213921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12931201 = 67 ⋅193003.

It can be written as a sum of positive squares in 2 ways, for example, as 7102225 + 3111696 = 2665^2 + 1764^2 .

It is a cyclic number.

It is not a de Polignac number, because 10213921 - 2⁷ = 10213793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10213927) 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, 1530 + ... + 4771.

It is an arithmetic number, because the mean of its divisors is an integer number (2555461).

Almost surely, 2^10213921 is an apocalyptic number.

It is an amenable number.

10213921 is a deficient number, since it is larger than the sum of its proper divisors (7923).

10213921 is an equidigital number, since it uses as much as digits as its factorization.

10213921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7922.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 10213921 is about 3195.9225585111. The cubic root of 10213921 is about 216.9689054811.

The spelling of 10213921 in words is "ten million, two hundred thirteen thousand, nine hundred twenty-one".