18259272507521 has 2 divisors, whose sum is σ = 18259272507522. Its totient is φ = 18259272507520.

The previous prime is 18259272507503. The next prime is 18259272507569. The reversal of 18259272507521 is 12570527295281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17143367607025 + 1115904900496 = 4140455^2 + 1056364^2 .

It is a cyclic number.

It is not a de Polignac number, because 18259272507521 - 2⁶ = 18259272507457 is a prime.

It is a super-3 number, since 3×18259272507521³ (a number of 41 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (18259272707521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9129636253760 + 9129636253761.

It is an arithmetic number, because the mean of its divisors is an integer number (9129636253761).

Almost surely, 2^{18259272507521} is an apocalyptic number.

It is an amenable number.

18259272507521 is a deficient number, since it is larger than the sum of its proper divisors (1).

18259272507521 is an equidigital number, since it uses as much as digits as its factorization.

18259272507521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056000, while the sum is 56.

The spelling of 18259272507521 in words is "eighteen trillion, two hundred fifty-nine billion, two hundred seventy-two million, five hundred seven thousand, five hundred twenty-one".