1097973861581 has 2 divisors, whose sum is σ = 1097973861582. Its totient is φ = 1097973861580.

The previous prime is 1097973861541. The next prime is 1097973861623. The reversal of 1097973861581 is 1851683797901.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 876077280100 + 221896581481 = 935990^2 + 471059^2 .

It is a cyclic number.

It is not a de Polignac number, because 1097973861581 - 2¹⁴ = 1097973845197 is a prime.

It is a super-2 number, since 2×1097973861581² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1097973861541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 548986930790 + 548986930791.

It is an arithmetic number, because the mean of its divisors is an integer number (548986930791).

Almost surely, 2^{1097973861581} is an apocalyptic number.

It is an amenable number.

1097973861581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1097973861581 is an equidigital number, since it uses as much as digits as its factorization.

1097973861581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22861440, while the sum is 65.

The spelling of 1097973861581 in words is "one trillion, ninety-seven billion, nine hundred seventy-three million, eight hundred sixty-one thousand, five hundred eighty-one".