20365421 has 2 divisors, whose sum is σ = 20365422. Its totient is φ = 20365420.

The previous prime is 20365393. The next prime is 20365447. The reversal of 20365421 is 12456302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12180100 + 8185321 = 3490^2 + 2861^2 .

It is a cyclic number.

It is not a de Polignac number, because 20365421 - 2¹⁴ = 20349037 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20361421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10182710 + 10182711.

It is an arithmetic number, because the mean of its divisors is an integer number (10182711).

Almost surely, 2^20365421 is an apocalyptic number.

It is an amenable number.

20365421 is a deficient number, since it is larger than the sum of its proper divisors (1).

20365421 is an equidigital number, since it uses as much as digits as its factorization.

20365421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 20365421 is about 4512.8063330925. The cubic root of 20365421 is about 273.0849695481.

The spelling of 20365421 in words is "twenty million, three hundred sixty-five thousand, four hundred twenty-one".