1000002121 has 4 divisors (see below), whose sum is σ = 1000226500. Its totient is φ = 999777744.

The previous prime is 1000002103. The next prime is 1000002139. The reversal of 1000002121 is 1212000001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1212000001 = 3457 ⋅350593.

It is an interprime number because it is at equal distance from previous prime (1000002103) and next prime (1000002139).

It can be written as a sum of positive squares in 2 ways, for example, as 578931721 + 421070400 = 24061^2 + 20520^2 .

It is a cyclic number.

It is not a de Polignac number, because 1000002121 - 2⁵ = 1000002089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1000002161) 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, 105366 + ... + 114463.

It is an arithmetic number, because the mean of its divisors is an integer number (250056625).

Almost surely, 2^1000002121 is an apocalyptic number.

It is an amenable number.

1000002121 is a deficient number, since it is larger than the sum of its proper divisors (224379).

1000002121 is an equidigital number, since it uses as much as digits as its factorization.

1000002121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224378.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 1000002121 is about 31622.8101376206. The cubic root of 1000002121 is about 1000.0007069995. Note that the first 3 decimals are identical.

Adding to 1000002121 its reverse (1212000001), we get a palindrome (2212002122).

The spelling of 1000002121 in words is "one billion, two thousand, one hundred twenty-one".