81219345 has 16 divisors (see below), whose sum is σ = 130946112. Its totient is φ = 42985280.

The previous prime is 81219331. The next prime is 81219367. The reversal of 81219345 is 54391218.

It is not a de Polignac number, because 81219345 - 2¹⁰ = 81218321 is a prime.

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, 18702 + ... + 22631.

It is an arithmetic number, because the mean of its divisors is an integer number (8184132).

Almost surely, 2^81219345 is an apocalyptic number.

It is an amenable number.

81219345 is a deficient number, since it is larger than the sum of its proper divisors (49726767).

81219345 is a wasteful number, since it uses less digits than its factorization.

81219345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41472.

The product of its digits is 8640, while the sum is 33.

The square root of 81219345 is about 9012.1775947881. The cubic root of 81219345 is about 433.0650749267.

The spelling of 81219345 in words is "eighty-one million, two hundred nineteen thousand, three hundred forty-five".