1155561440 has 96 divisors (see below), whose sum is σ = 3016258560. Its totient is φ = 414835200.

The previous prime is 1155561439. The next prime is 1155561481. The reversal of 1155561440 is 441655511.

It is a super-2 number, since 2×1155561440² = 2670644483229747200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 1155561397 and 1155561406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 134885 + ... + 143195.

It is an arithmetic number, because the mean of its divisors is an integer number (31419360).

Almost surely, 2^1155561440 is an apocalyptic number.

1155561440 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 1155561440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1508129280).

1155561440 is an abundant number, since it is smaller than the sum of its proper divisors (1860697120).

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

1155561440 is a wasteful number, since it uses less digits than its factorization.

1155561440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8416 (or 8408 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 32.

The square root of 1155561440 is about 33993.5499764294. The cubic root of 1155561440 is about 1049.3757256629.

The spelling of 1155561440 in words is "one billion, one hundred fifty-five million, five hundred sixty-one thousand, four hundred forty".