1081991232 has 168 divisors, whose sum is σ = 3573979136. Its totient is φ = 306561024.

The previous prime is 1081991219. The next prime is 1081991257. The reversal of 1081991232 is 2321991801.

It is a tau number, because it is divible by the number of its divisors (168).

It is a super-2 number, since 2×1081991232² = 2341410052249755648, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 511008 + ... + 513120.

Almost surely, 2^1081991232 is an apocalyptic number.

1081991232 is a gapful number since it is divisible by the number (12) 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 1081991232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1786989568).

1081991232 is an abundant number, since it is smaller than the sum of its proper divisors (2491987904).

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

1081991232 is a wasteful number, since it uses less digits than its factorization.

1081991232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2265 (or 2252 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 1081991232 is about 32893.6351290033. The cubic root of 1081991232 is about 1026.6157288121.

The spelling of 1081991232 in words is "one billion, eighty-one million, nine hundred ninety-one thousand, two hundred thirty-two".