121642861 has 2 divisors, whose sum is σ = 121642862. Its totient is φ = 121642860.

The previous prime is 121642841. The next prime is 121642867. The reversal of 121642861 is 168246121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71318025 + 50324836 = 8445^2 + 7094^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121642861 is a prime.

It is a plaindrome in base 14.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121642867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60821430 + 60821431.

It is an arithmetic number, because the mean of its divisors is an integer number (60821431).

Almost surely, 2^121642861 is an apocalyptic number.

It is an amenable number.

121642861 is a deficient number, since it is larger than the sum of its proper divisors (1).

121642861 is an equidigital number, since it uses as much as digits as its factorization.

121642861 is an evil number, because the sum of its binary digits is even.

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

The square root of 121642861 is about 11029.1822452982. The cubic root of 121642861 is about 495.4831333697.

Adding to 121642861 its reverse (168246121), we get a palindrome (289888982).

The spelling of 121642861 in words is "one hundred twenty-one million, six hundred forty-two thousand, eight hundred sixty-one".