121215889 has 2 divisors, whose sum is σ = 121215890. Its totient is φ = 121215888.

The previous prime is 121215847. The next prime is 121215907. The reversal of 121215889 is 988512121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76860289 + 44355600 = 8767^2 + 6660^2 .

It is an emirp because it is prime and its reverse (988512121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121215889 - 2¹⁹ = 120691601 is a prime.

It is not a weakly prime, because it can be changed into another prime (121210889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60607944 + 60607945.

It is an arithmetic number, because the mean of its divisors is an integer number (60607945).

Almost surely, 2^121215889 is an apocalyptic number.

It is an amenable number.

121215889 is a deficient number, since it is larger than the sum of its proper divisors (1).

121215889 is an equidigital number, since it uses as much as digits as its factorization.

121215889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 37.

The square root of 121215889 is about 11009.8087630985. The cubic root of 121215889 is about 494.9027309471.

The spelling of 121215889 in words is "one hundred twenty-one million, two hundred fifteen thousand, eight hundred eighty-nine".