18430981 has 8 divisors (see below), whose sum is σ = 19309824. Its totient is φ = 17558640.

The previous prime is 18430943. The next prime is 18431011. The reversal of 18430981 is 18903481.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18430981 is a prime.

It is a super-2 number, since 2×18430981² = 679402121244722, which 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 (18430081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4755 + ... + 7711.

It is an arithmetic number, because the mean of its divisors is an integer number (2413728).

Almost surely, 2^18430981 is an apocalyptic number.

It is an amenable number.

18430981 is a deficient number, since it is larger than the sum of its proper divisors (878843).

18430981 is a wasteful number, since it uses less digits than its factorization.

18430981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3251.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 18430981 is about 4293.1318405099. The cubic root of 18430981 is about 264.1493119633.

The spelling of 18430981 in words is "eighteen million, four hundred thirty thousand, nine hundred eighty-one".