1002171220 has 12 divisors (see below), whose sum is σ = 2104559604. Its totient is φ = 400868480.

The previous prime is 1002171211. The next prime is 1002171253. The reversal of 1002171220 is 221712001.

It can be written as a sum of positive squares in 2 ways, for example, as 253382724 + 748788496 = 15918^2 + 27364^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1002171194 and 1002171203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25054261 + ... + 25054300.

It is an arithmetic number, because the mean of its divisors is an integer number (175379967).

Almost surely, 2^1002171220 is an apocalyptic number.

1002171220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1002171220 is an abundant number, since it is smaller than the sum of its proper divisors (1102388384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1002171220 is a wasteful number, since it uses less digits than its factorization.

1002171220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50108570 (or 50108568 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 1002171220 is about 31657.0879898957. The cubic root of 1002171220 is about 1000.7232168313.

Adding to 1002171220 its reverse (221712001), we get a palindrome (1223883221).

The spelling of 1002171220 in words is "one billion, two million, one hundred seventy-one thousand, two hundred twenty".