1001121220 has 48 divisors (see below), whose sum is σ = 2297030400. Its totient is φ = 363480320.

The previous prime is 1001121193. The next prime is 1001121283. The reversal of 1001121220 is 221211001.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 1001121197 and 1001121206.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 155016 + ... + 161344.

It is an arithmetic number, because the mean of its divisors is an integer number (47854800).

Almost surely, 2^1001121220 is an apocalyptic number.

1001121220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1001121220 is an abundant number, since it is smaller than the sum of its proper divisors (1295909180).

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

1001121220 is a wasteful number, since it uses less digits than its factorization.

1001121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7068 (or 7066 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1001121220 is about 31640.4996799987. The cubic root of 1001121220 is about 1000.3736004054.

Adding to 1001121220 its reverse (221211001), we get a palindrome (1222332221).

It can be divided in two parts, 1001 and 121220, that added together give a palindrome (122221).

The spelling of 1001121220 in words is "one billion, one million, one hundred twenty-one thousand, two hundred twenty".