81652218 has 16 divisors (see below), whose sum is σ = 164750976. Its totient is φ = 26976320.

The previous prime is 81652217. The next prime is 81652243. The reversal of 81652218 is 81225618.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81652217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59538 + ... + 60893.

It is an arithmetic number, because the mean of its divisors is an integer number (10296936).

Almost surely, 2^81652218 is an apocalyptic number.

81652218 is an abundant number, since it is smaller than the sum of its proper divisors (83098758).

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

81652218 is a wasteful number, since it uses less digits than its factorization.

81652218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120549.

The product of its digits is 7680, while the sum is 33.

The square root of 81652218 is about 9036.1616851404. The cubic root of 81652218 is about 433.8330780138.

The spelling of 81652218 in words is "eighty-one million, six hundred fifty-two thousand, two hundred eighteen".