121856587 has 2 divisors, whose sum is σ = 121856588. Its totient is φ = 121856586.

The previous prime is 121856569. The next prime is 121856597. The reversal of 121856587 is 785658121.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121856587 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (121856597) 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, 60928293 + 60928294.

It is an arithmetic number, because the mean of its divisors is an integer number (60928294).

Almost surely, 2^121856587 is an apocalyptic number.

121856587 is a deficient number, since it is larger than the sum of its proper divisors (1).

121856587 is an equidigital number, since it uses as much as digits as its factorization.

121856587 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 134400, while the sum is 43.

The square root of 121856587 is about 11038.8671067279. The cubic root of 121856587 is about 495.7731508498.

The spelling of 121856587 in words is "one hundred twenty-one million, eight hundred fifty-six thousand, five hundred eighty-seven".