81216146 has 32 divisors (see below), whose sum is σ = 140555520. Its totient is φ = 34808400.

The previous prime is 81216133. The next prime is 81216199. The reversal of 81216146 is 64161218.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138065 + ... + 138651.

It is an arithmetic number, because the mean of its divisors is an integer number (4392360).

Almost surely, 2^81216146 is an apocalyptic number.

81216146 is a deficient number, since it is larger than the sum of its proper divisors (59339374).

81216146 is a wasteful number, since it uses less digits than its factorization.

81216146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 950.

The product of its digits is 2304, while the sum is 29.

The square root of 81216146 is about 9012.0001109632. Note that the first 3 decimals coincide. The cubic root of 81216146 is about 433.0593891164.

The spelling of 81216146 in words is "eighty-one million, two hundred sixteen thousand, one hundred forty-six".