18415306981 has 4 divisors (see below), whose sum is σ = 18426971200. Its totient is φ = 18403642764.

The previous prime is 18415306951. The next prime is 18415306999. The reversal of 18415306981 is 18960351481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18415306981 - 2⁷ = 18415306853 is a prime.

It is a super-2 number, since 2×18415306981² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18415306951) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5829741 + ... + 5832898.

It is an arithmetic number, because the mean of its divisors is an integer number (4606742800).

Almost surely, 2^18415306981 is an apocalyptic number.

It is an amenable number.

18415306981 is a deficient number, since it is larger than the sum of its proper divisors (11664219).

18415306981 is a wasteful number, since it uses less digits than its factorization.

18415306981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11664218.

The product of its (nonzero) digits is 207360, while the sum is 46.

The spelling of 18415306981 in words is "eighteen billion, four hundred fifteen million, three hundred six thousand, nine hundred eighty-one".