18281131421 has 16 divisors (see below), whose sum is σ = 21913944576. Its totient is φ = 14921646336.

The previous prime is 18281131411. The next prime is 18281131529. The reversal of 18281131421 is 12413118281.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18281131421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18281131411) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 738716 + ... + 763061.

It is an arithmetic number, because the mean of its divisors is an integer number (1369621536).

Almost surely, 2^18281131421 is an apocalyptic number.

It is an amenable number.

18281131421 is a deficient number, since it is larger than the sum of its proper divisors (3632813155).

18281131421 is a wasteful number, since it uses less digits than its factorization.

18281131421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1501868.

The product of its digits is 3072, while the sum is 32.

The spelling of 18281131421 in words is "eighteen billion, two hundred eighty-one million, one hundred thirty-one thousand, four hundred twenty-one".