121201999 has 4 divisors (see below), whose sum is σ = 121409064. Its totient is φ = 120994936.

The previous prime is 121201981. The next prime is 121202017. The reversal of 121201999 is 999102121.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (121201981) and next prime (121202017).

It is a cyclic number.

It is not a de Polignac number, because 121201999 - 2¹⁷ = 121070927 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 (121201799) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102652 + ... + 103825.

It is an arithmetic number, because the mean of its divisors is an integer number (30352266).

Almost surely, 2^121201999 is an apocalyptic number.

121201999 is a deficient number, since it is larger than the sum of its proper divisors (207065).

121201999 is an equidigital number, since it uses as much as digits as its factorization.

121201999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207064.

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 121201999 is about 11009.1779438794. The cubic root of 121201999 is about 494.8838267655.

The spelling of 121201999 in words is "one hundred twenty-one million, two hundred one thousand, nine hundred ninety-nine".