18731013 has 16 divisors (see below), whose sum is σ = 29527680. Its totient is φ = 10334016.

The previous prime is 18730981. The next prime is 18731021. The reversal of 18731013 is 31013781.

It is not a de Polignac number, because 18731013 - 2⁵ = 18730981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18731023) 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, 14770 + ... + 15987.

It is an arithmetic number, because the mean of its divisors is an integer number (1845480).

Almost surely, 2^18731013 is an apocalyptic number.

It is an amenable number.

18731013 is a deficient number, since it is larger than the sum of its proper divisors (10796667).

18731013 is a wasteful number, since it uses less digits than its factorization.

18731013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30796.

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 18731013 is about 4327.9340336932. The cubic root of 18731013 is about 265.5749377949.

Adding to 18731013 its reverse (31013781), we get a palindrome (49744794).

The spelling of 18731013 in words is "eighteen million, seven hundred thirty-one thousand, thirteen".