1081520640 has 160 divisors (see below), whose sum is σ = 3841896960. Its totient is φ = 288387072.

The previous prime is 1081520639. The next prime is 1081520647. The reversal of 1081520640 is 460251801.

1081520640 is a `hidden beast` number, since 1 + 0 + 8 + 15 + 2 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1081520647) 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, 61297 + ... + 76943.

It is an arithmetic number, because the mean of its divisors is an integer number (24011856).

Almost surely, 2^1081520640 is an apocalyptic number.

1081520640 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 1081520640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1920948480).

1081520640 is an abundant number, since it is smaller than the sum of its proper divisors (2760376320).

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

1081520640 is an equidigital number, since it uses as much as digits as its factorization.

1081520640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15679 (or 15657 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 1081520640 is about 32886.4811130653. The cubic root of 1081520640 is about 1026.4668714115.

The spelling of 1081520640 in words is "one billion, eighty-one million, five hundred twenty thousand, six hundred forty".