900000121 has 4 divisors (see below), whose sum is σ = 900378612. Its totient is φ = 899621632.

The previous prime is 900000107. The next prime is 900000131. The reversal of 900000121 is 121000009.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18800896 + 881199225 = 4336^2 + 29685^2 .

It is a cyclic number.

It is not a de Polignac number, because 900000121 - 2⁹ = 899999609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (900000131) 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 3 ways as a sum of consecutive naturals, for example, 185656 + ... + 190441.

It is an arithmetic number, because the mean of its divisors is an integer number (225094653).

Almost surely, 2^900000121 is an apocalyptic number.

It is an amenable number.

900000121 is a deficient number, since it is larger than the sum of its proper divisors (378491).

900000121 is a wasteful number, since it uses less digits than its factorization.

900000121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378490.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 900000121 is about 30000.0020166666. The cubic root of 900000121 is about 965.4894278739.

The spelling of 900000121 in words is "nine hundred million, one hundred twenty-one", and thus it is an aban number.