18372444949 has 2 divisors, whose sum is σ = 18372444950. Its totient is φ = 18372444948.

The previous prime is 18372444947. The next prime is 18372445019. The reversal of 18372444949 is 94944427381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13896165924 + 4476279025 = 117882^2 + 66905^2 .

It is a cyclic number.

It is not a de Polignac number, because 18372444949 - 2¹ = 18372444947 is a prime.

It is a super-2 number, since 2×18372444949² (a number of 21 digits) contains 22 as substring.

Together with 18372444947, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 18372444949.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18372444947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9186222474 + 9186222475.

It is an arithmetic number, because the mean of its divisors is an integer number (9186222475).

Almost surely, 2^18372444949 is an apocalyptic number.

It is an amenable number.

18372444949 is a deficient number, since it is larger than the sum of its proper divisors (1).

18372444949 is an equidigital number, since it uses as much as digits as its factorization.

18372444949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6967296, while the sum is 55.

The spelling of 18372444949 in words is "eighteen billion, three hundred seventy-two million, four hundred forty-four thousand, nine hundred forty-nine".