140566681 has 2 divisors, whose sum is σ = 140566682. Its totient is φ = 140566680.

The previous prime is 140566667. The next prime is 140566687. The reversal of 140566681 is 186665041.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138768400 + 1798281 = 11780^2 + 1341^2 .

It is an emirp because it is prime and its reverse (186665041) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 140566681 - 2⁷ = 140566553 is a prime.

It is a super-2 number, since 2×140566681² = 39517983614711522, which contains 22 as substring.

It is equal to p_7942285 and since 140566681 and 7942285 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 140566681.

It is not a weakly prime, because it can be changed into another prime (140566687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 70283340 + 70283341.

It is an arithmetic number, because the mean of its divisors is an integer number (70283341).

Almost surely, 2^140566681 is an apocalyptic number.

It is an amenable number.

140566681 is a deficient number, since it is larger than the sum of its proper divisors (1).

140566681 is an equidigital number, since it uses as much as digits as its factorization.

140566681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 140566681 is about 11856.0820256947. The cubic root of 140566681 is about 519.9490593590.

It can be divided in two parts, 1405 and 66681, that added together give a palindrome (68086).

The spelling of 140566681 in words is "one hundred forty million, five hundred sixty-six thousand, six hundred eighty-one".