81702810 has 128 divisors (see below), whose sum is σ = 251596800. Its totient is φ = 18480960.

The previous prime is 81702781. The next prime is 81702811. The reversal of 81702810 is 1820718.

It is a super-2 number, since 2×81702810² = 13350698323792200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (81702811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 262555 + ... + 262865.

It is an arithmetic number, because the mean of its divisors is an integer number (1965600).

Almost surely, 2^81702810 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81702810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125798400).

81702810 is an abundant number, since it is smaller than the sum of its proper divisors (169893990).

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

81702810 is a wasteful number, since it uses less digits than its factorization.

81702810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473 (or 467 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 81702810 is about 9038.9606703426. The cubic root of 81702810 is about 433.9226610121.

The spelling of 81702810 in words is "eighty-one million, seven hundred two thousand, eight hundred ten".