121642681 has 2 divisors, whose sum is σ = 121642682. Its totient is φ = 121642680.

The previous prime is 121642649. The next prime is 121642751. The reversal of 121642681 is 186246121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115347600 + 6295081 = 10740^2 + 2509^2 .

It is a cyclic number.

It is not a de Polignac number, because 121642681 - 2⁵ = 121642649 is a prime.

It is a super-2 number, since 2×121642681² = 29593883681735522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (121642621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60821340 + 60821341.

It is an arithmetic number, because the mean of its divisors is an integer number (60821341).

Almost surely, 2^121642681 is an apocalyptic number.

It is an amenable number.

121642681 is a deficient number, since it is larger than the sum of its proper divisors (1).

121642681 is an equidigital number, since it uses as much as digits as its factorization.

121642681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4608, while the sum is 31.

The square root of 121642681 is about 11029.1740851253. The cubic root of 121642681 is about 495.4828889739.

The spelling of 121642681 in words is "one hundred twenty-one million, six hundred forty-two thousand, six hundred eighty-one".