1081661040 has 280 divisors, whose sum is σ = 3996025488. Its totient is φ = 271226880.

The previous prime is 1081661029. The next prime is 1081661041. The reversal of 1081661040 is 401661801.

1081661040 is a `hidden beast` number, since 1 + 0 + 8 + 1 + 6 + 610 + 40 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 1081660995 and 1081661013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1081661041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 990895 + ... + 991985.

Almost surely, 2^1081661040 is an apocalyptic number.

1081661040 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 1081661040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1998012744).

1081661040 is an abundant number, since it is smaller than the sum of its proper divisors (2914364448).

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

1081661040 is a wasteful number, since it uses less digits than its factorization.

1081661040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1139 (or 1118 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1081661040 is about 32888.6156595257. The cubic root of 1081661040 is about 1026.5112871806.

The spelling of 1081661040 in words is "one billion, eighty-one million, six hundred sixty-one thousand, forty".