40663398961 has 2 divisors, whose sum is σ = 40663398962. Its totient is φ = 40663398960.

The previous prime is 40663398949. The next prime is 40663398991. The reversal of 40663398961 is 16989336604.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38259360000 + 2404038961 = 195600^2 + 49031^2 .

It is a cyclic number.

It is not a de Polignac number, because 40663398961 - 2¹¹ = 40663396913 is a prime.

It is a super-2 number, since 2×40663398961² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (40663398911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20331699480 + 20331699481.

It is an arithmetic number, because the mean of its divisors is an integer number (20331699481).

Almost surely, 2^40663398961 is an apocalyptic number.

It is an amenable number.

40663398961 is a deficient number, since it is larger than the sum of its proper divisors (1).

40663398961 is an equidigital number, since it uses as much as digits as its factorization.

40663398961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5038848, while the sum is 55.

The spelling of 40663398961 in words is "forty billion, six hundred sixty-three million, three hundred ninety-eight thousand, nine hundred sixty-one".