18948338977 has 2 divisors, whose sum is σ = 18948338978. Its totient is φ = 18948338976.

The previous prime is 18948338963. The next prime is 18948338989. The reversal of 18948338977 is 77983384981.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18746812561 + 201526416 = 136919^2 + 14196^2 .

It is an emirp because it is prime and its reverse (77983384981) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18948338977 is a prime.

It is not a weakly prime, because it can be changed into another prime (18948338077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9474169488 + 9474169489.

It is an arithmetic number, because the mean of its divisors is an integer number (9474169489).

Almost surely, 2^18948338977 is an apocalyptic number.

It is an amenable number.

18948338977 is a deficient number, since it is larger than the sum of its proper divisors (1).

18948338977 is an equidigital number, since it uses as much as digits as its factorization.

18948338977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 73156608, while the sum is 67.

The spelling of 18948338977 in words is "eighteen billion, nine hundred forty-eight million, three hundred thirty-eight thousand, nine hundred seventy-seven".