20013421 has 2 divisors, whose sum is σ = 20013422. Its totient is φ = 20013420.

The previous prime is 20013407. The next prime is 20013439. The reversal of 20013421 is 12431002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19272100 + 741321 = 4390^2 + 861^2 .

It is a cyclic number.

It is not a de Polignac number, because 20013421 - 2⁷ = 20013293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20013481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10006710 + 10006711.

It is an arithmetic number, because the mean of its divisors is an integer number (10006711).

Almost surely, 2^20013421 is an apocalyptic number.

It is an amenable number.

20013421 is a deficient number, since it is larger than the sum of its proper divisors (1).

20013421 is an equidigital number, since it uses as much as digits as its factorization.

20013421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 20013421 is about 4473.6362167704. The cubic root of 20013421 is about 271.5024650812.

Adding to 20013421 its reverse (12431002), we get a palindrome (32444423).

The spelling of 20013421 in words is "twenty million, thirteen thousand, four hundred twenty-one".