18935381 has 4 divisors (see below), whose sum is σ = 19932000. Its totient is φ = 17938764.

The previous prime is 18935359. The next prime is 18935383. The reversal of 18935381 is 18353981.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18935381 is a prime.

It is a super-2 number, since 2×18935381² = 717097307230322, 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 (18935383) 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, 498281 + ... + 498318.

It is an arithmetic number, because the mean of its divisors is an integer number (4983000).

Almost surely, 2^18935381 is an apocalyptic number.

It is an amenable number.

18935381 is a deficient number, since it is larger than the sum of its proper divisors (996619).

18935381 is an equidigital number, since it uses as much as digits as its factorization.

18935381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 996618.

The product of its digits is 25920, while the sum is 38.

The square root of 18935381 is about 4351.4803228327. The cubic root of 18935381 is about 266.5373134795.

The spelling of 18935381 in words is "eighteen million, nine hundred thirty-five thousand, three hundred eighty-one".