172989612731581 has 2 divisors, whose sum is σ = 172989612731582. Its totient is φ = 172989612731580.

The previous prime is 172989612731563. The next prime is 172989612731699. The reversal of 172989612731581 is 185137216989271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 127081318111225 + 45908294620356 = 11273035^2 + 6775566^2 .

It is a cyclic number.

It is not a de Polignac number, because 172989612731581 - 2¹⁵ = 172989612698813 is a prime.

It is a super-2 number, since 2×172989612731581² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 172989612731581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172989612731281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86494806365790 + 86494806365791.

It is an arithmetic number, because the mean of its divisors is an integer number (86494806365791).

Almost surely, 2^{172989612731581} is an apocalyptic number.

It is an amenable number.

172989612731581 is a deficient number, since it is larger than the sum of its proper divisors (1).

172989612731581 is an equidigital number, since it uses as much as digits as its factorization.

172989612731581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 91445760, while the sum is 70.

The spelling of 172989612731581 in words is "one hundred seventy-two trillion, nine hundred eighty-nine billion, six hundred twelve million, seven hundred thirty-one thousand, five hundred eighty-one".