189318005281 has 2 divisors, whose sum is σ = 189318005282. Its totient is φ = 189318005280.

The previous prime is 189318005273. The next prime is 189318005347. The reversal of 189318005281 is 182500813981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 187908378256 + 1409627025 = 433484^2 + 37545^2 .

It is a cyclic number.

It is not a de Polignac number, because 189318005281 - 2³ = 189318005273 is a prime.

It is a super-2 number, since 2×189318005281² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (189348005281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94659002640 + 94659002641.

It is an arithmetic number, because the mean of its divisors is an integer number (94659002641).

Almost surely, 2^189318005281 is an apocalyptic number.

It is an amenable number.

189318005281 is a deficient number, since it is larger than the sum of its proper divisors (1).

189318005281 is an equidigital number, since it uses as much as digits as its factorization.

189318005281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 138240, while the sum is 46.

The spelling of 189318005281 in words is "one hundred eighty-nine billion, three hundred eighteen million, five thousand, two hundred eighty-one".