18906738278401 has 2 divisors, whose sum is σ = 18906738278402. Its totient is φ = 18906738278400.

The previous prime is 18906738278359. The next prime is 18906738278419. The reversal of 18906738278401 is 10487283760981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13681861210000 + 5224877068401 = 3698900^2 + 2285799^2 .

It is an emirp because it is prime and its reverse (10487283760981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18906738278401 - 2¹¹ = 18906738276353 is a prime.

It is not a weakly prime, because it can be changed into another prime (18906738278201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9453369139200 + 9453369139201.

It is an arithmetic number, because the mean of its divisors is an integer number (9453369139201).

Almost surely, 2^{18906738278401} is an apocalyptic number.

It is an amenable number.

18906738278401 is a deficient number, since it is larger than the sum of its proper divisors (1).

18906738278401 is an equidigital number, since it uses as much as digits as its factorization.

18906738278401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32514048, while the sum is 64.

The spelling of 18906738278401 in words is "eighteen trillion, nine hundred six billion, seven hundred thirty-eight million, two hundred seventy-eight thousand, four hundred one".