81210732 has 12 divisors (see below), whose sum is σ = 189491736. Its totient is φ = 27070240.

The previous prime is 81210721. The next prime is 81210737. The reversal of 81210732 is 23701218.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (81210737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3383769 + ... + 3383792.

It is an arithmetic number, because the mean of its divisors is an integer number (15790978).

Almost surely, 2^81210732 is an apocalyptic number.

It is an amenable number.

81210732 is an abundant number, since it is smaller than the sum of its proper divisors (108281004).

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

81210732 is a wasteful number, since it uses less digits than its factorization.

81210732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6767568 (or 6767566 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 81210732 is about 9011.6997286860. The cubic root of 81210732 is about 433.0497660888.

The spelling of 81210732 in words is "eighty-one million, two hundred ten thousand, seven hundred thirty-two".