81051432 has 128 divisors (see below), whose sum is σ = 257126400. Its totient is φ = 20678400.

The previous prime is 81051413. The next prime is 81051457. The reversal of 81051432 is 23415018.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 112369 + ... + 113087.

It is an arithmetic number, because the mean of its divisors is an integer number (2008800).

Almost surely, 2^81051432 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81051432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128563200).

81051432 is an abundant number, since it is smaller than the sum of its proper divisors (176074968).

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

81051432 is a wasteful number, since it uses less digits than its factorization.

81051432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 807 (or 803 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 81051432 is about 9002.8568799021. The cubic root of 81051432 is about 432.7664292223.

The spelling of 81051432 in words is "eighty-one million, fifty-one thousand, four hundred thirty-two".