12978421 has 8 divisors (see below), whose sum is σ = 13296024. Its totient is φ = 12664320.

The previous prime is 12978419. The next prime is 12978431. The reversal of 12978421 is 12487921.

It can be written as a sum of positive squares in 4 ways, for example, as 119025 + 12859396 = 345^2 + 3586^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12978421 - 2¹ = 12978419 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 (12978401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7581 + ... + 9133.

It is an arithmetic number, because the mean of its divisors is an integer number (1662003).

Almost surely, 2^12978421 is an apocalyptic number.

It is an amenable number.

12978421 is a deficient number, since it is larger than the sum of its proper divisors (317603).

12978421 is a wasteful number, since it uses less digits than its factorization.

12978421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1751.

The product of its digits is 8064, while the sum is 34.

The square root of 12978421 is about 3602.5575637316. The cubic root of 12978421 is about 235.0032955627.

The spelling of 12978421 in words is "twelve million, nine hundred seventy-eight thousand, four hundred twenty-one".