1125121998 has 128 divisors (see below), whose sum is σ = 3119284224. Its totient is φ = 261014400.

The previous prime is 1125121997. The next prime is 1125122023. The reversal of 1125121998 is 8991215211.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1125121997) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 183165 + ... + 189207.

It is an arithmetic number, because the mean of its divisors is an integer number (24369408).

Almost surely, 2^1125121998 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1125121998, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1559642112).

1125121998 is an abundant number, since it is smaller than the sum of its proper divisors (1994162226).

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

1125121998 is a wasteful number, since it uses less digits than its factorization.

1125121998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6110.

The product of its digits is 12960, while the sum is 39.

The square root of 1125121998 is about 33542.8382520025. The cubic root of 1125121998 is about 1040.0795051398.

The spelling of 1125121998 in words is "one billion, one hundred twenty-five million, one hundred twenty-one thousand, nine hundred ninety-eight".