12921989 has 4 divisors (see below), whose sum is σ = 13682124. Its totient is φ = 12161856.

The previous prime is 12921967. The next prime is 12922001. The reversal of 12921989 is 98912921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9150625 + 3771364 = 3025^2 + 1942^2 .

It is a cyclic number.

It is not a de Polignac number, because 12921989 - 2¹⁶ = 12856453 is a prime.

It is a super-2 number, since 2×12921989² = 333955599432242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12921089) 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, 380042 + ... + 380075.

It is an arithmetic number, because the mean of its divisors is an integer number (3420531).

Almost surely, 2^12921989 is an apocalyptic number.

It is an amenable number.

12921989 is a deficient number, since it is larger than the sum of its proper divisors (760135).

12921989 is an equidigital number, since it uses as much as digits as its factorization.

12921989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760134.

The product of its digits is 23328, while the sum is 41.

The square root of 12921989 is about 3594.7168177758. The cubic root of 12921989 is about 234.6621915666.

The spelling of 12921989 in words is "twelve million, nine hundred twenty-one thousand, nine hundred eighty-nine".