17906960561981 has 32 divisors (see below), whose sum is σ = 19775147868000. Its totient is φ = 16139178639360.

The previous prime is 17906960561911. The next prime is 17906960561983. The reversal of 17906960561981 is 18916506960971.

It can be written as a sum of positive squares in 16 ways, for example, as 8806234300900 + 9100726261081 = 2967530^2 + 3016741^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17906960561981 is a prime.

It is a super-2 number, since 2×17906960561981² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17906960561983) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49255451 + ... + 49617671.

It is an arithmetic number, because the mean of its divisors is an integer number (617973370875).

Almost surely, 2^{17906960561981} is an apocalyptic number.

It is an amenable number.

17906960561981 is a deficient number, since it is larger than the sum of its proper divisors (1868187306019).

17906960561981 is a wasteful number, since it uses less digits than its factorization.

17906960561981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363089.

The product of its (nonzero) digits is 44089920, while the sum is 68.

The spelling of 17906960561981 in words is "seventeen trillion, nine hundred six billion, nine hundred sixty million, five hundred sixty-one thousand, nine hundred eighty-one".