18411921 has 32 divisors (see below), whose sum is σ = 30412800. Its totient is φ = 10913040.

The previous prime is 18411907. The next prime is 18411929. The reversal of 18411921 is 12911481.

It is not a de Polignac number, because 18411921 - 2⁶ = 18411857 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (18411929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13300 + ... + 14618.

It is an arithmetic number, because the mean of its divisors is an integer number (950400).

Almost surely, 2^18411921 is an apocalyptic number.

18411921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18411921 is a deficient number, since it is larger than the sum of its proper divisors (12000879).

18411921 is a wasteful number, since it uses less digits than its factorization.

18411921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1386 (or 1380 counting only the distinct ones).

The product of its digits is 576, while the sum is 27.

The square root of 18411921 is about 4290.9114416403. The cubic root of 18411921 is about 264.0582257936.

The spelling of 18411921 in words is "eighteen million, four hundred eleven thousand, nine hundred twenty-one".