81837070 has 32 divisors (see below), whose sum is σ = 168739776. Its totient is φ = 27993600.

The previous prime is 81837053. The next prime is 81837079. The reversal of 81837070 is 7073818.

It is a happy number.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81837079) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36790 + ... + 38950.

It is an arithmetic number, because the mean of its divisors is an integer number (5273118).

Almost surely, 2^81837070 is an apocalyptic number.

81837070 is an abundant number, since it is smaller than the sum of its proper divisors (86902706).

81837070 is a wasteful number, since it uses less digits than its factorization.

81837070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2716.

The product of its (nonzero) digits is 9408, while the sum is 34.

The square root of 81837070 is about 9046.3843606161. The cubic root of 81837070 is about 434.1602153633.

The spelling of 81837070 in words is "eighty-one million, eight hundred thirty-seven thousand, seventy".