81285119 has 4 divisors (see below), whose sum is σ = 81311400. Its totient is φ = 81258840.

The previous prime is 81285101. The next prime is 81285121. The reversal of 81285119 is 91158218.

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 81285119 - 2¹⁶ = 81219583 is a prime.

It is a super-2 number, since 2×81285119² = 13214541141688322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81285019) 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, 7769 + ... + 14930.

It is an arithmetic number, because the mean of its divisors is an integer number (20327850).

Almost surely, 2^81285119 is an apocalyptic number.

81285119 is a deficient number, since it is larger than the sum of its proper divisors (26281).

81285119 is a wasteful number, since it uses less digits than its factorization.

81285119 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26280.

The product of its digits is 5760, while the sum is 35.

The square root of 81285119 is about 9015.8260298211. The cubic root of 81285119 is about 433.1819466584.

The spelling of 81285119 in words is "eighty-one million, two hundred eighty-five thousand, one hundred nineteen".