1001121000 has 256 divisors, whose sum is σ = 3558297600. Its totient is φ = 231968000.

The previous prime is 1001120999. The next prime is 1001121031. The reversal of 1001121000 is 1211001.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a self number, because there is not a number n which added to its sum of digits gives 1001121000.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 758341 + ... + 759659.

It is an arithmetic number, because the mean of its divisors is an integer number (13899600).

Almost surely, 2^1001121000 is an apocalyptic number.

1001121000 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 1001121000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1779148800).

1001121000 is an abundant number, since it is smaller than the sum of its proper divisors (2557176600).

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

1001121000 is a wasteful number, since it uses less digits than its factorization.

1001121000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1377 (or 1363 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 6.

The square root of 1001121000 is about 31640.4962034416. The cubic root of 1001121000 is about 1000.3735271268.

Adding to 1001121000 its reverse (1211001), we get a palindrome (1002332001).

Subtracting from 1001121000 its reverse (1211001), we obtain a palindrome (999909999).

The spelling of 1001121000 in words is "one billion, one million, one hundred twenty-one thousand".