81674281 has 16 divisors (see below), whose sum is σ = 90808144. Its totient is φ = 72969984.

The previous prime is 81674279. The next prime is 81674323. The reversal of 81674281 is 18247618.

It can be written as a sum of positive squares in 8 ways, for example, as 19501056 + 62173225 = 4416^2 + 7885^2 .

It is a cyclic number.

It is not a de Polignac number, because 81674281 - 2¹ = 81674279 is a prime.

It is a super-2 number, since 2×81674281² = 13341376353733922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

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 81674281.

It is not an unprimeable number, because it can be changed into a prime (81674881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 132931 + ... + 133543.

It is an arithmetic number, because the mean of its divisors is an integer number (5675509).

Almost surely, 2^81674281 is an apocalyptic number.

It is an amenable number.

81674281 is a deficient number, since it is larger than the sum of its proper divisors (9133863).

81674281 is a wasteful number, since it uses less digits than its factorization.

81674281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 940.

The product of its digits is 21504, while the sum is 37.

The square root of 81674281 is about 9037.3824197054. The cubic root of 81674281 is about 433.8721494048.

The spelling of 81674281 in words is "eighty-one million, six hundred seventy-four thousand, two hundred eighty-one".