10212991 has 4 divisors (see below), whose sum is σ = 10221552. Its totient is φ = 10204432.

The previous prime is 10212967. The next prime is 10213001. The reversal of 10212991 is 19921201.

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.

It is a cyclic number.

It is not a de Polignac number, because 10212991 - 2⁷ = 10212863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10212911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2131 + ... + 4996.

It is an arithmetic number, because the mean of its divisors is an integer number (2555388).

Almost surely, 2^10212991 is an apocalyptic number.

10212991 is a deficient number, since it is larger than the sum of its proper divisors (8561).

10212991 is an equidigital number, since it uses as much as digits as its factorization.

10212991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8560.

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 10212991 is about 3195.7770573055. Note that the first 3 decimals coincide. The cubic root of 10212991 is about 216.9623201157.

The spelling of 10212991 in words is "ten million, two hundred twelve thousand, nine hundred ninety-one".