1155640980 has 192 divisors, whose sum is σ = 3736631808. Its totient is φ = 264591360.

The previous prime is 1155640979. The next prime is 1155641023. The reversal of 1155640980 is 890465511.

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

It is a congruent number.

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, 662910 + ... + 664650.

It is an arithmetic number, because the mean of its divisors is an integer number (19461624).

Almost surely, 2^1155640980 is an apocalyptic number.

1155640980 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 1155640980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1868315904).

1155640980 is an abundant number, since it is smaller than the sum of its proper divisors (2580990828).

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

1155640980 is a wasteful number, since it uses less digits than its factorization.

1155640980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1826 (or 1824 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 39.

The square root of 1155640980 is about 33994.7198841232. The cubic root of 1155640980 is about 1049.3998021067.

The spelling of 1155640980 in words is "one billion, one hundred fifty-five million, six hundred forty thousand, nine hundred eighty".