18764421 has 32 divisors (see below), whose sum is σ = 28546560. Its totient is φ = 10881024.

The previous prime is 18764411. The next prime is 18764443. The reversal of 18764421 is 12446781.

It is not a de Polignac number, because 18764421 - 2⁶ = 18764357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18764401) 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, 52981 + ... + 53333.

It is an arithmetic number, because the mean of its divisors is an integer number (892080).

Almost surely, 2^18764421 is an apocalyptic number.

It is an amenable number.

18764421 is a deficient number, since it is larger than the sum of its proper divisors (9782139).

18764421 is a wasteful number, since it uses less digits than its factorization.

18764421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445.

The product of its digits is 10752, while the sum is 33.

The square root of 18764421 is about 4331.7918925082. The cubic root of 18764421 is about 265.7327341716.

The spelling of 18764421 in words is "eighteen million, seven hundred sixty-four thousand, four hundred twenty-one".