1002020121 has 12 divisors (see below), whose sum is σ = 1465684480. Its totient is φ = 659557080.

The previous prime is 1002020087. The next prime is 1002020177. The reversal of 1002020121 is 1210202001.

It is not a de Polignac number, because 1002020121 - 2⁶ = 1002020057 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1002020191) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 703945 + ... + 705366.

Almost surely, 2^1002020121 is an apocalyptic number.

It is an amenable number.

1002020121 is a deficient number, since it is larger than the sum of its proper divisors (463664359).

1002020121 is a wasteful number, since it uses less digits than its factorization.

1002020121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1409396 (or 1409393 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1002020121 is about 31654.7014043728. The cubic root of 1002020121 is about 1000.6729207428.

Adding to 1002020121 its reverse (1210202001), we get a palindrome (2212222122).

The spelling of 1002020121 in words is "one billion, two million, twenty thousand, one hundred twenty-one".