81442700 has 36 divisors (see below), whose sum is σ = 178108392. Its totient is φ = 32323200.

The previous prime is 81442679. The next prime is 81442703. The reversal of 81442700 is 724418.

It is a self number, because there is not a number n which added to its sum of digits gives 81442700.

It is not an unprimeable number, because it can be changed into a prime (81442703) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9992 + ... + 16208.

Almost surely, 2^81442700 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 81442700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89054196).

81442700 is an abundant number, since it is smaller than the sum of its proper divisors (96665692).

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

81442700 is a wasteful number, since it uses less digits than its factorization.

81442700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6362 (or 6355 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 81442700 is about 9024.5609311478. The cubic root of 81442700 is about 433.4616911009.

The spelling of 81442700 in words is "eighty-one million, four hundred forty-two thousand, seven hundred".