121521981 has 8 divisors (see below), whose sum is σ = 185176384. Its totient is φ = 69441120.

The previous prime is 121521973. The next prime is 121521997. The reversal of 121521981 is 189125121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 121521981 - 2³ = 121521973 is a prime.

It is a super-2 number, since 2×121521981² = 29535183732328722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121521941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2893360 + ... + 2893401.

It is an arithmetic number, because the mean of its divisors is an integer number (23147048).

Almost surely, 2^121521981 is an apocalyptic number.

It is an amenable number.

121521981 is a deficient number, since it is larger than the sum of its proper divisors (63654403).

121521981 is an equidigital number, since it uses as much as digits as its factorization.

121521981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5786771.

The product of its digits is 1440, while the sum is 30.

The square root of 121521981 is about 11023.7008758402. The cubic root of 121521981 is about 495.3189537072.

The spelling of 121521981 in words is "one hundred twenty-one million, five hundred twenty-one thousand, nine hundred eighty-one".