1100400120 has 64 divisors (see below), whose sum is σ = 3668004000. Its totient is φ = 293439744.

The previous prime is 1100400113. The next prime is 1100400121. The reversal of 1100400120 is 210040011.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1100400121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 508365 + ... + 510524.

Almost surely, 2^1100400120 is an apocalyptic number.

1100400120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1100400120 is an abundant number, since it is smaller than the sum of its proper divisors (2567603880).

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

1100400120 is a wasteful number, since it uses less digits than its factorization.

1100400120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1018909 (or 1018899 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1100400120 is about 33172.2793910819. The cubic root of 1100400120 is about 1032.4052626836.

Adding to 1100400120 its reverse (210040011), we get a palindrome (1310440131).

The spelling of 1100400120 in words is "one billion, one hundred million, four hundred thousand, one hundred twenty".