181920019213 has 4 divisors (see below), whose sum is σ = 181943104608. Its totient is φ = 181896933820.

The previous prime is 181920019201. The next prime is 181920019301. The reversal of 181920019213 is 312910029181.

181920019213 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 312910029181 = 67 ⋅4670298943.

It is a cyclic number.

It is not a de Polignac number, because 181920019213 - 2⁵ = 181920019181 is a prime.

It is a super-3 number, since 3×181920019213³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181920019313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11530873 + ... + 11546638.

It is an arithmetic number, because the mean of its divisors is an integer number (45485776152).

Almost surely, 2^181920019213 is an apocalyptic number.

It is an amenable number.

181920019213 is a deficient number, since it is larger than the sum of its proper divisors (23085395).

181920019213 is an equidigital number, since it uses as much as digits as its factorization.

181920019213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23085394.

The product of its (nonzero) digits is 7776, while the sum is 37.

The spelling of 181920019213 in words is "one hundred eighty-one billion, nine hundred twenty million, nineteen thousand, two hundred thirteen".