121660681 has 2 divisors, whose sum is σ = 121660682. Its totient is φ = 121660680.

The previous prime is 121660633. The next prime is 121660703. The reversal of 121660681 is 186066121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120012025 + 1648656 = 10955^2 + 1284^2 .

It is an emirp because it is prime and its reverse (186066121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121660681 - 2¹¹ = 121658633 is a prime.

It is a super-2 number, since 2×121660681² = 29602642602767522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (121660081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60830340 + 60830341.

It is an arithmetic number, because the mean of its divisors is an integer number (60830341).

Almost surely, 2^121660681 is an apocalyptic number.

It is an amenable number.

121660681 is a deficient number, since it is larger than the sum of its proper divisors (1).

121660681 is an equidigital number, since it uses as much as digits as its factorization.

121660681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 121660681 is about 11029.9900725250. The cubic root of 121660681 is about 495.5073273592.

The spelling of 121660681 in words is "one hundred twenty-one million, six hundred sixty thousand, six hundred eighty-one".