900121021 has 4 divisors (see below), whose sum is σ = 921054112. Its totient is φ = 879187932.

The previous prime is 900121003. The next prime is 900121037. The reversal of 900121021 is 120121009.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 900121021 - 2⁹ = 900120509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 900120986 and 900121004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (900121121) 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, 10466481 + ... + 10466566.

It is an arithmetic number, because the mean of its divisors is an integer number (230263528).

Almost surely, 2^900121021 is an apocalyptic number.

It is an amenable number.

900121021 is a deficient number, since it is larger than the sum of its proper divisors (20933091).

900121021 is a wasteful number, since it uses less digits than its factorization.

900121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20933090.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 900121021 is about 30002.0169488653. The cubic root of 900121021 is about 965.5326584034.

The spelling of 900121021 in words is "nine hundred million, one hundred twenty-one thousand, twenty-one".