18020437 has 4 divisors (see below), whose sum is σ = 18315916. Its totient is φ = 17724960.

The previous prime is 18020413. The next prime is 18020441. The reversal of 18020437 is 73402081.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6791236 + 11229201 = 2606^2 + 3351^2 .

It is a cyclic number.

It is not a de Polignac number, because 18020437 - 2⁷ = 18020309 is a prime.

It is a super-2 number, since 2×18020437² = 649472299341938, which contains 22 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 (18020447) 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, 147648 + ... + 147769.

It is an arithmetic number, because the mean of its divisors is an integer number (4578979).

Almost surely, 2^18020437 is an apocalyptic number.

It is an amenable number.

18020437 is a deficient number, since it is larger than the sum of its proper divisors (295479).

18020437 is an equidigital number, since it uses as much as digits as its factorization.

18020437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295478.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 18020437 is about 4245.0485274022. The cubic root of 18020437 is about 262.1732872619.

The spelling of 18020437 in words is "eighteen million, twenty thousand, four hundred thirty-seven".