121201981 has 2 divisors, whose sum is σ = 121201982. Its totient is φ = 121201980.

The previous prime is 121201963. The next prime is 121202017. The reversal of 121201981 is 189102121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61387225 + 59814756 = 7835^2 + 7734^2 .

It is a cyclic number.

It is not a de Polignac number, because 121201981 - 2¹³ = 121193789 is a prime.

It is a super-2 number, since 2×121201981² = 29379840396648722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121201481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60600990 + 60600991.

It is an arithmetic number, because the mean of its divisors is an integer number (60600991).

Almost surely, 2^121201981 is an apocalyptic number.

It is an amenable number.

121201981 is a deficient number, since it is larger than the sum of its proper divisors (1).

121201981 is an equidigital number, since it uses as much as digits as its factorization.

121201981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 25.

The square root of 121201981 is about 11009.1771263796. The cubic root of 121201981 is about 494.8838022667.

The spelling of 121201981 in words is "one hundred twenty-one million, two hundred one thousand, nine hundred eighty-one".