18331968247 has 2 divisors, whose sum is σ = 18331968248. Its totient is φ = 18331968246.

The previous prime is 18331968223. The next prime is 18331968287. The reversal of 18331968247 is 74286913381.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18331968247 is a prime.

It is a super-2 number, since 2×18331968247² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18331968194 and 18331968203.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18331968217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9165984123 + 9165984124.

It is an arithmetic number, because the mean of its divisors is an integer number (9165984124).

Almost surely, 2^18331968247 is an apocalyptic number.

18331968247 is a deficient number, since it is larger than the sum of its proper divisors (1).

18331968247 is an equidigital number, since it uses as much as digits as its factorization.

18331968247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1741824, while the sum is 52.

The spelling of 18331968247 in words is "eighteen billion, three hundred thirty-one million, nine hundred sixty-eight thousand, two hundred forty-seven".