121217381 has 2 divisors, whose sum is σ = 121217382. Its totient is φ = 121217380.

The previous prime is 121217353. The next prime is 121217389. The reversal of 121217381 is 183712121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 106708900 + 14508481 = 10330^2 + 3809^2 .

It is a cyclic number.

It is not a de Polignac number, because 121217381 - 2¹⁰ = 121216357 is a prime.

It is a super-2 number, since 2×121217381² = 29387306912998322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 121217381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121217389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60608690 + 60608691.

It is an arithmetic number, because the mean of its divisors is an integer number (60608691).

Almost surely, 2^121217381 is an apocalyptic number.

It is an amenable number.

121217381 is a deficient number, since it is larger than the sum of its proper divisors (1).

121217381 is an equidigital number, since it uses as much as digits as its factorization.

121217381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 672, while the sum is 26.

The square root of 121217381 is about 11009.8765206518. The cubic root of 121217381 is about 494.9047614616.

The spelling of 121217381 in words is "one hundred twenty-one million, two hundred seventeen thousand, three hundred eighty-one".