20438240213 has 2 divisors, whose sum is σ = 20438240214. Its totient is φ = 20438240212.

The previous prime is 20438240203. The next prime is 20438240287. The reversal of 20438240213 is 31204283402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18518310724 + 1919929489 = 136082^2 + 43817^2 .

It is a cyclic number.

It is not a de Polignac number, because 20438240213 - 2⁶ = 20438240149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20438240203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10219120106 + 10219120107.

It is an arithmetic number, because the mean of its divisors is an integer number (10219120107).

Almost surely, 2^20438240213 is an apocalyptic number.

It is an amenable number.

20438240213 is a deficient number, since it is larger than the sum of its proper divisors (1).

20438240213 is an equidigital number, since it uses as much as digits as its factorization.

20438240213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 29.

The spelling of 20438240213 in words is "twenty billion, four hundred thirty-eight million, two hundred forty thousand, two hundred thirteen".