10131221 has 4 divisors (see below), whose sum is σ = 10188000. Its totient is φ = 10074444.

The previous prime is 10131211. The next prime is 10131227. The reversal of 10131221 is 12213101.

10131221 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 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 10131221 - 2⁶ = 10131157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10131227) 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, 28121 + ... + 28478.

It is an arithmetic number, because the mean of its divisors is an integer number (2547000).

Almost surely, 2^10131221 is an apocalyptic number.

It is an amenable number.

10131221 is a deficient number, since it is larger than the sum of its proper divisors (56779).

10131221 is an equidigital number, since it uses as much as digits as its factorization.

10131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56778.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 10131221 is about 3182.9579010725. The cubic root of 10131221 is about 216.3817338060.

Adding to 10131221 its reverse (12213101), we get a palindrome (22344322).

The spelling of 10131221 in words is "ten million, one hundred thirty-one thousand, two hundred twenty-one".