121667989 has 2 divisors, whose sum is σ = 121667990. Its totient is φ = 121667988.

The previous prime is 121667981. The next prime is 121668011. The reversal of 121667989 is 989766121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118919025 + 2748964 = 10905^2 + 1658^2 .

It is an emirp because it is prime and its reverse (989766121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121667989 - 2³ = 121667981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121667981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60833994 + 60833995.

It is an arithmetic number, because the mean of its divisors is an integer number (60833995).

Almost surely, 2^121667989 is an apocalyptic number.

It is an amenable number.

121667989 is a deficient number, since it is larger than the sum of its proper divisors (1).

121667989 is an equidigital number, since it uses as much as digits as its factorization.

121667989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 49.

The square root of 121667989 is about 11030.3213461803. The cubic root of 121667989 is about 495.5172486556.

The spelling of 121667989 in words is "one hundred twenty-one million, six hundred sixty-seven thousand, nine hundred eighty-nine".