81001332 has 36 divisors (see below), whose sum is σ = 215531680. Its totient is φ = 25579152.

The previous prime is 81001309. The next prime is 81001339. The reversal of 81001332 is 23310018.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×81001332² = 13122431571548448, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81001339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58528 + ... + 59895.

Almost surely, 2^81001332 is an apocalyptic number.

It is an amenable number.

81001332 is an abundant number, since it is smaller than the sum of its proper divisors (134530348).

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

81001332 is a wasteful number, since it uses less digits than its factorization.

81001332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118452 (or 118447 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 81001332 is about 9000.0739996958. The cubic root of 81001332 is about 432.6772427785.

The spelling of 81001332 in words is "eighty-one million, one thousand, three hundred thirty-two".