1002022121 has 4 divisors (see below), whose sum is σ = 1003319172. Its totient is φ = 1000725072.

The previous prime is 1002022103. The next prime is 1002022157. The reversal of 1002022121 is 1212202001.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1212202001 = 29 ⋅41800069.

It can be written as a sum of positive squares in 2 ways, for example, as 105678400 + 896343721 = 10280^2 + 29939^2 .

It is a cyclic number.

It is not a de Polignac number, because 1002022121 - 2¹⁸ = 1001759977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1002022621) 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, 647366 + ... + 648911.

It is an arithmetic number, because the mean of its divisors is an integer number (250829793).

Almost surely, 2^1002022121 is an apocalyptic number.

It is an amenable number.

1002022121 is a deficient number, since it is larger than the sum of its proper divisors (1297051).

1002022121 is an equidigital number, since it uses as much as digits as its factorization.

1002022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1297050.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1002022121 is about 31654.7329952410. The cubic root of 1002022121 is about 1000.6735865127.

Adding to 1002022121 its reverse (1212202001), we get a palindrome (2214224122).

The spelling of 1002022121 in words is "one billion, two million, twenty-two thousand, one hundred twenty-one".