18201813 has 16 divisors (see below), whose sum is σ = 27801600. Its totient is φ = 10376496.

The previous prime is 18201797. The next prime is 18201839. The reversal of 18201813 is 31810281.

It is not a de Polignac number, because 18201813 - 2⁴ = 18201797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18201013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11856 + ... + 13302.

It is an arithmetic number, because the mean of its divisors is an integer number (1737600).

Almost surely, 2^18201813 is an apocalyptic number.

It is an amenable number.

18201813 is a deficient number, since it is larger than the sum of its proper divisors (9599787).

18201813 is a wasteful number, since it uses less digits than its factorization.

18201813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2056.

The product of its (nonzero) digits is 384, while the sum is 24.

The square root of 18201813 is about 4266.3582831263. The cubic root of 18201813 is about 263.0499454557.

The spelling of 18201813 in words is "eighteen million, two hundred one thousand, eight hundred thirteen".