121781331 has 12 divisors (see below), whose sum is σ = 201035952. Its totient is φ = 69589296.

The previous prime is 121781327. The next prime is 121781339. The reversal of 121781331 is 133187121.

It is a happy number.

It is not a de Polignac number, because 121781331 - 2² = 121781327 is a prime.

It is a super-2 number, since 2×121781331² = 29661385160263122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 121781295 and 121781304.

It is not an unprimeable number, because it can be changed into a prime (121781339) 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 11 ways as a sum of consecutive naturals, for example, 966456 + ... + 966581.

It is an arithmetic number, because the mean of its divisors is an integer number (16752996).

Almost surely, 2^121781331 is an apocalyptic number.

121781331 is a deficient number, since it is larger than the sum of its proper divisors (79254621).

121781331 is a wasteful number, since it uses less digits than its factorization.

121781331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1933050 (or 1933047 counting only the distinct ones).

The product of its digits is 1008, while the sum is 27.

The square root of 121781331 is about 11035.4578971604. The cubic root of 121781331 is about 495.6710702308.

The spelling of 121781331 in words is "one hundred twenty-one million, seven hundred eighty-one thousand, three hundred thirty-one".