18773880397 has 2 divisors, whose sum is σ = 18773880398. Its totient is φ = 18773880396.

The previous prime is 18773880383. The next prime is 18773880407. The reversal of 18773880397 is 79308837781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16347923881 + 2425956516 = 127859^2 + 49254^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18773880397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18773880337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9386940198 + 9386940199.

It is an arithmetic number, because the mean of its divisors is an integer number (9386940199).

Almost surely, 2^18773880397 is an apocalyptic number.

It is an amenable number.

18773880397 is a deficient number, since it is larger than the sum of its proper divisors (1).

18773880397 is an equidigital number, since it uses as much as digits as its factorization.

18773880397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14224896, while the sum is 61.

The spelling of 18773880397 in words is "eighteen billion, seven hundred seventy-three million, eight hundred eighty thousand, three hundred ninety-seven".