121231999 has 8 divisors (see below), whose sum is σ = 139353120. Its totient is φ = 103311456.

The previous prime is 121231993. The next prime is 121232009. The reversal of 121231999 is 999132121.

It is a happy number.

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 121231999 - 2³ = 121231991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121231991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48844 + ... + 51265.

It is an arithmetic number, because the mean of its divisors is an integer number (17419140).

Almost surely, 2^121231999 is an apocalyptic number.

121231999 is a deficient number, since it is larger than the sum of its proper divisors (18121121).

121231999 is a wasteful number, since it uses less digits than its factorization.

121231999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100289.

The product of its digits is 8748, while the sum is 37.

The square root of 121231999 is about 11010.5403591286. The cubic root of 121231999 is about 494.9246547226.

The spelling of 121231999 in words is "one hundred twenty-one million, two hundred thirty-one thousand, nine hundred ninety-nine".