81700512 has 48 divisors (see below), whose sum is σ = 215228160. Its totient is φ = 27136512.

The previous prime is 81700499. The next prime is 81700519. The reversal of 81700512 is 21500718.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×81700512² = 13349947322124288, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (81700519) 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 7 ways as a sum of consecutive naturals, for example, 28689 + ... + 31407.

It is an arithmetic number, because the mean of its divisors is an integer number (4483920).

Almost surely, 2^81700512 is an apocalyptic number.

It is an amenable number.

81700512 is an abundant number, since it is smaller than the sum of its proper divisors (133527648).

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

81700512 is a wasteful number, since it uses less digits than its factorization.

81700512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3045 (or 3037 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 24.

The square root of 81700512 is about 9038.8335530642. The cubic root of 81700512 is about 433.9185927570.

The spelling of 81700512 in words is "eighty-one million, seven hundred thousand, five hundred twelve".