18936381 has 8 divisors (see below), whose sum is σ = 26063104. Its totient is φ = 12216960.

The previous prime is 18936373. The next prime is 18936403. The reversal of 18936381 is 18363981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18936381 - 2³ = 18936373 is a prime.

It is a super-2 number, since 2×18936381² = 717173050754322, 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 (18936311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 101716 + ... + 101901.

It is an arithmetic number, because the mean of its divisors is an integer number (3257888).

Almost surely, 2^18936381 is an apocalyptic number.

It is an amenable number.

18936381 is a deficient number, since it is larger than the sum of its proper divisors (7126723).

18936381 is a wasteful number, since it uses less digits than its factorization.

18936381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203651.

The product of its digits is 31104, while the sum is 39.

The square root of 18936381 is about 4351.5952247423. The cubic root of 18936381 is about 266.5420054478.

The spelling of 18936381 in words is "eighteen million, nine hundred thirty-six thousand, three hundred eighty-one".