81283531 has 8 divisors (see below), whose sum is σ = 93433824. Its totient is φ = 69267840.

The previous prime is 81283507. The next prime is 81283547. The reversal of 81283531 is 13538218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81283531 - 2⁹ = 81283019 is a prime.

It is a super-2 number, since 2×81283531² = 13214024823655922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81283493 and 81283502.

It is not an unprimeable number, because it can be changed into a prime (81283571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32350 + ... + 34771.

It is an arithmetic number, because the mean of its divisors is an integer number (11679228).

Almost surely, 2^81283531 is an apocalyptic number.

81283531 is a deficient number, since it is larger than the sum of its proper divisors (12150293).

81283531 is a wasteful number, since it uses less digits than its factorization.

81283531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67301.

The product of its digits is 5760, while the sum is 31.

The square root of 81283531 is about 9015.7379620306. The cubic root of 81283531 is about 433.1791257345.

The spelling of 81283531 in words is "eighty-one million, two hundred eighty-three thousand, five hundred thirty-one".