2001011121000 has 320 divisors, whose sum is σ = 7109329415760. Its totient is φ = 524854080000.

The previous prime is 2001011120989. The next prime is 2001011121073. The reversal of 2001011121000 is 1211101002.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 66970193796 + 1934040927204 = 258786^2 + 1390698^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 4738510 + ... + 5143490.

Almost surely, 2^{2001011121000} is an apocalyptic number.

2001011121000 is a gapful number since it is divisible by the number (20) 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 2001011121000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3554664707880).

2001011121000 is an abundant number, since it is smaller than the sum of its proper divisors (5108318294760).

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

2001011121000 is a wasteful number, since it uses less digits than its factorization.

2001011121000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405075 (or 405052 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 2001011121000 its reverse (1211101002), we get a palindrome (2002222222002).

The spelling of 2001011121000 in words is "two trillion, one billion, eleven million, one hundred twenty-one thousand".