18406416857 has 2 divisors, whose sum is σ = 18406416858. Its totient is φ = 18406416856.

The previous prime is 18406416823. The next prime is 18406416907. The reversal of 18406416857 is 75861460481.

It is an a-pointer prime, because the next prime (18406416907) can be obtained adding 18406416857 to its sum of digits (50).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13146686281 + 5259730576 = 114659^2 + 72524^2 .

It is an emirp because it is prime and its reverse (75861460481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18406416857 - 2¹⁴ = 18406400473 is a prime.

It is not a weakly prime, because it can be changed into another prime (18406416157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9203208428 + 9203208429.

It is an arithmetic number, because the mean of its divisors is an integer number (9203208429).

Almost surely, 2^18406416857 is an apocalyptic number.

It is an amenable number.

18406416857 is a deficient number, since it is larger than the sum of its proper divisors (1).

18406416857 is an equidigital number, since it uses as much as digits as its factorization.

18406416857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1290240, while the sum is 50.

The spelling of 18406416857 in words is "eighteen billion, four hundred six million, four hundred sixteen thousand, eight hundred fifty-seven".