18201920213 has 4 divisors (see below), whose sum is σ = 19272621420. Its totient is φ = 17131219008.

The previous prime is 18201920207. The next prime is 18201920237. The reversal of 18201920213 is 31202910281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31202910281 = 269 ⋅115995949.

It can be written as a sum of positive squares in 2 ways, for example, as 8633754724 + 9568165489 = 92918^2 + 97817^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18201920213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18201920263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 535350578 + ... + 535350611.

It is an arithmetic number, because the mean of its divisors is an integer number (4818155355).

Almost surely, 2^18201920213 is an apocalyptic number.

It is an amenable number.

18201920213 is a deficient number, since it is larger than the sum of its proper divisors (1070701207).

18201920213 is a wasteful number, since it uses less digits than its factorization.

18201920213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1070701206.

The product of its (nonzero) digits is 1728, while the sum is 29.

The spelling of 18201920213 in words is "eighteen billion, two hundred one million, nine hundred twenty thousand, two hundred thirteen".