20181235213 has 2 divisors, whose sum is σ = 20181235214. Its totient is φ = 20181235212.

The previous prime is 20181235183. The next prime is 20181235229. The reversal of 20181235213 is 31253218102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16316996644 + 3864238569 = 127738^2 + 62163^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20181235213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20181235813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10090617606 + 10090617607.

It is an arithmetic number, because the mean of its divisors is an integer number (10090617607).

Almost surely, 2^20181235213 is an apocalyptic number.

It is an amenable number.

20181235213 is a deficient number, since it is larger than the sum of its proper divisors (1).

20181235213 is an equidigital number, since it uses as much as digits as its factorization.

20181235213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

The spelling of 20181235213 in words is "twenty billion, one hundred eighty-one million, two hundred thirty-five thousand, two hundred thirteen".