18729031 has 2 divisors, whose sum is σ = 18729032. Its totient is φ = 18729030.

The previous prime is 18729023. The next prime is 18729049. The reversal of 18729031 is 13092781.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18729031 - 2³ = 18729023 is a prime.

It is a super-2 number, since 2×18729031² = 701553204397922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18728984 and 18729002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18729091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9364515 + 9364516.

It is an arithmetic number, because the mean of its divisors is an integer number (9364516).

Almost surely, 2^18729031 is an apocalyptic number.

18729031 is a deficient number, since it is larger than the sum of its proper divisors (1).

18729031 is an equidigital number, since it uses as much as digits as its factorization.

18729031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 18729031 is about 4327.7050500236. The cubic root of 18729031 is about 265.5655702985.

The spelling of 18729031 in words is "eighteen million, seven hundred twenty-nine thousand, thirty-one".