18681838 has 32 divisors (see below), whose sum is σ = 33105600. Its totient is φ = 7902720.

The previous prime is 18681833. The next prime is 18681851. The reversal of 18681838 is 83818681.

It is a super-2 number, since 2×18681838² = 698022142116488, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18681794 and 18681803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18681833) 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, 77398 + ... + 77638.

It is an arithmetic number, because the mean of its divisors is an integer number (1034550).

Almost surely, 2^18681838 is an apocalyptic number.

18681838 is a deficient number, since it is larger than the sum of its proper divisors (14423762).

18681838 is a wasteful number, since it uses less digits than its factorization.

18681838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377 (or 363 counting only the distinct ones).

The product of its digits is 73728, while the sum is 43.

The square root of 18681838 is about 4322.2491830065. The cubic root of 18681838 is about 265.3423272598.

The spelling of 18681838 in words is "eighteen million, six hundred eighty-one thousand, eight hundred thirty-eight".