81053215 has 4 divisors (see below), whose sum is σ = 97263864. Its totient is φ = 64842568.

The previous prime is 81053213. The next prime is 81053227. The reversal of 81053215 is 51235018.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81053215 - 2¹ = 81053213 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81053215.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81053213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8105317 + ... + 8105326.

It is an arithmetic number, because the mean of its divisors is an integer number (24315966).

Almost surely, 2^81053215 is an apocalyptic number.

81053215 is a deficient number, since it is larger than the sum of its proper divisors (16210649).

81053215 is a wasteful number, since it uses less digits than its factorization.

81053215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16210648.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 81053215 is about 9002.9559034797. The cubic root of 81053215 is about 432.7696025855.

The spelling of 81053215 in words is "eighty-one million, fifty-three thousand, two hundred fifteen".