11111121000 has 256 divisors, whose sum is σ = 44021952000. Its totient is φ = 2539641600.

The previous prime is 11111120981. The next prime is 11111121019. The reversal of 11111121000 is 12111111.

It is an interprime number because it is at equal distance from previous prime (11111120981) and next prime (11111121019).

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

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

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, 159606 + ... + 218394.

It is an arithmetic number, because the mean of its divisors is an integer number (171960750).

Almost surely, 2^11111121000 is an apocalyptic number.

11111121000 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 11111121000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22010976000).

11111121000 is an abundant number, since it is smaller than the sum of its proper divisors (32910831000).

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

11111121000 is a wasteful number, since it uses less digits than its factorization.

11111121000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58826 (or 58806 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 9.

Adding to 11111121000 its reverse (12111111), we get a palindrome (11123232111).

The spelling of 11111121000 in words is "eleven billion, one hundred eleven million, one hundred twenty-one thousand".