10491221 has 4 divisors (see below), whose sum is σ = 11298252. Its totient is φ = 9684192.

The previous prime is 10491181. The next prime is 10491233. The reversal of 10491221 is 12219401.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12219401 = 1427 ⋅8563.

It can be written as a sum of positive squares in 2 ways, for example, as 1575025 + 8916196 = 1255^2 + 2986^2 .

It is a cyclic number.

It is not a de Polignac number, because 10491221 - 2¹⁸ = 10229077 is a prime.

It is a super-2 number, since 2×10491221² = 220131436141682, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a junction number, because it is equal to n+sod(n) for n = 10491193 and 10491202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10491241) 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, 403496 + ... + 403521.

It is an arithmetic number, because the mean of its divisors is an integer number (2824563).

Almost surely, 2^10491221 is an apocalyptic number.

It is an amenable number.

10491221 is a deficient number, since it is larger than the sum of its proper divisors (807031).

10491221 is an equidigital number, since it uses as much as digits as its factorization.

10491221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807030.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 10491221 is about 3239.0154368264. The cubic root of 10491221 is about 218.9149117264.

The spelling of 10491221 in words is "ten million, four hundred ninety-one thousand, two hundred twenty-one".