121783981 has 8 divisors (see below), whose sum is σ = 136096128. Its totient is φ = 108012000.

The previous prime is 121783979. The next prime is 121783993. The reversal of 121783981 is 189387121.

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

It is a cyclic number.

It is not a de Polignac number, because 121783981 - 2¹ = 121783979 is a prime.

It is a super-2 number, since 2×121783981² = 29662676056416722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121783481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134565 + ... + 135466.

It is an arithmetic number, because the mean of its divisors is an integer number (17012016).

Almost surely, 2^121783981 is an apocalyptic number.

121783981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121783981 is a deficient number, since it is larger than the sum of its proper divisors (14312147).

121783981 is a wasteful number, since it uses less digits than its factorization.

121783981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270083.

The product of its digits is 24192, while the sum is 40.

The square root of 121783981 is about 11035.5779640216. The cubic root of 121783981 is about 495.6746655241.

The spelling of 121783981 in words is "one hundred twenty-one million, seven hundred eighty-three thousand, nine hundred eighty-one".