18973949 has 2 divisors, whose sum is σ = 18973950. Its totient is φ = 18973948.

The previous prime is 18973937. The next prime is 18973979. The reversal of 18973949 is 94937981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18705625 + 268324 = 4325^2 + 518^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18973949 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18973897 and 18973906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18973979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9486974 + 9486975.

It is an arithmetic number, because the mean of its divisors is an integer number (9486975).

Almost surely, 2^18973949 is an apocalyptic number.

It is an amenable number.

18973949 is a deficient number, since it is larger than the sum of its proper divisors (1).

18973949 is an equidigital number, since it uses as much as digits as its factorization.

18973949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 50.

The square root of 18973949 is about 4355.9096638934. The cubic root of 18973949 is about 266.7181537737.

The spelling of 18973949 in words is "eighteen million, nine hundred seventy-three thousand, nine hundred forty-nine".