10213981 has 2 divisors, whose sum is σ = 10213982. Its totient is φ = 10213980.

The previous prime is 10213967. The next prime is 10213999. The reversal of 10213981 is 18931201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9865881 + 348100 = 3141^2 + 590^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10213981 is a prime.

It is a super-2 number, since 2×10213981² = 208650815736722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10213781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5106990 + 5106991.

It is an arithmetic number, because the mean of its divisors is an integer number (5106991).

Almost surely, 2^10213981 is an apocalyptic number.

It is an amenable number.

10213981 is a deficient number, since it is larger than the sum of its proper divisors (1).

10213981 is an equidigital number, since it uses as much as digits as its factorization.

10213981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 10213981 is about 3195.9319454582. The cubic root of 10213981 is about 216.9693303297.

The spelling of 10213981 in words is "ten million, two hundred thirteen thousand, nine hundred eighty-one".