18810421821 has 12 divisors (see below), whose sum is σ = 28351940448. Its totient is φ = 11995051464.

The previous prime is 18810421789. The next prime is 18810421829. The reversal of 18810421821 is 12812401881.

It is not a de Polignac number, because 18810421821 - 2⁵ = 18810421789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18810421829) 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 in 11 ways as a sum of consecutive naturals, for example, 45435595 + ... + 45436008.

It is an arithmetic number, because the mean of its divisors is an integer number (2362661704).

Almost surely, 2^18810421821 is an apocalyptic number.

It is an amenable number.

18810421821 is a deficient number, since it is larger than the sum of its proper divisors (9541518627).

18810421821 is a wasteful number, since it uses less digits than its factorization.

18810421821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90871632 (or 90871629 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 36.

The spelling of 18810421821 in words is "eighteen billion, eight hundred ten million, four hundred twenty-one thousand, eight hundred twenty-one".