1001122020 has 72 divisors (see below), whose sum is σ = 3058978104. Its totient is φ = 265010688.

The previous prime is 1001122009. The next prime is 1001122097. The reversal of 1001122020 is 202211001.

It can be written as a sum of positive squares in 4 ways, for example, as 404492544 + 596629476 = 20112^2 + 24426^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 1001121993 and 1001122011.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4362 + ... + 44958.

It is an arithmetic number, because the mean of its divisors is an integer number (42485807).

Almost surely, 2^1001122020 is an apocalyptic number.

1001122020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1001122020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1529489052).

1001122020 is an abundant number, since it is smaller than the sum of its proper divisors (2057856084).

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

1001122020 is a wasteful number, since it uses less digits than its factorization.

1001122020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40749 (or 40744 counting only the distinct ones).

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

The square root of 1001122020 is about 31640.5123220216. The cubic root of 1001122020 is about 1000.3738668728.

Adding to 1001122020 its reverse (202211001), we get a palindrome (1203333021).

The spelling of 1001122020 in words is "one billion, one million, one hundred twenty-two thousand, twenty".