81437100 has 72 divisors (see below), whose sum is σ = 236599440. Its totient is φ = 21626880.

The previous prime is 81437077. The next prime is 81437101. The reversal of 81437100 is 173418.

It is not an unprimeable number, because it can be changed into a prime (81437101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 105516 + ... + 106284.

Almost surely, 2^81437100 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 81437100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118299720).

81437100 is an abundant number, since it is smaller than the sum of its proper divisors (155162340).

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

81437100 is a wasteful number, since it uses less digits than its factorization.

81437100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1139 (or 1132 counting only the distinct ones).

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

The square root of 81437100 is about 9024.2506614123. The cubic root of 81437100 is about 433.4517559314.

The spelling of 81437100 in words is "eighty-one million, four hundred thirty-seven thousand, one hundred".