18721882 has 4 divisors (see below), whose sum is σ = 28082826. Its totient is φ = 9360940.

The previous prime is 18721867. The next prime is 18721883. The reversal of 18721882 is 28812781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 28812781 = 431 ⋅66851.

It can be written as a sum of positive squares in only one way, i.e., 18653761 + 68121 = 4319^2 + 261^2 .

It is not an unprimeable number, because it can be changed into a prime (18721883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4680469 + ... + 4680472.

Almost surely, 2^18721882 is an apocalyptic number.

18721882 is a deficient number, since it is larger than the sum of its proper divisors (9360944).

18721882 is an equidigital number, since it uses as much as digits as its factorization.

18721882 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9360943.

The product of its digits is 14336, while the sum is 37.

The square root of 18721882 is about 4326.8790137927. The cubic root of 18721882 is about 265.5317765965.

The spelling of 18721882 in words is "eighteen million, seven hundred twenty-one thousand, eight hundred eighty-two".