18421641 has 32 divisors (see below), whose sum is σ = 32275200. Its totient is φ = 10160640.

The previous prime is 18421639. The next prime is 18421681. The reversal of 18421641 is 14612481.

It is a happy number.

18421641 is a `hidden beast` number, since 18 + 4 + 2 + 1 + 641 = 666.

It is not a de Polignac number, because 18421641 - 2¹ = 18421639 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 (18421631) 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, 3801 + ... + 7161.

It is an arithmetic number, because the mean of its divisors is an integer number (1008600).

Almost surely, 2^18421641 is an apocalyptic number.

It is an amenable number.

18421641 is a deficient number, since it is larger than the sum of its proper divisors (13853559).

18421641 is a wasteful number, since it uses less digits than its factorization.

18421641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3406 (or 3400 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 18421641 is about 4292.0439186942. The cubic root of 18421641 is about 264.1046847232.

The spelling of 18421641 in words is "eighteen million, four hundred twenty-one thousand, six hundred forty-one".