81746281 has 4 divisors (see below), whose sum is σ = 82174464. Its totient is φ = 81318100.

The previous prime is 81746279. The next prime is 81746309. The reversal of 81746281 is 18264718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81746281 - 2¹ = 81746279 is a prime.

It is a super-2 number, since 2×81746281² = 13364908914661922, which contains 22 as substring.

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 81746281.

It is not an unprimeable number, because it can be changed into a prime (81746201) 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, 213805 + ... + 214186.

It is an arithmetic number, because the mean of its divisors is an integer number (20543616).

Almost surely, 2^81746281 is an apocalyptic number.

It is an amenable number.

81746281 is a deficient number, since it is larger than the sum of its proper divisors (428183).

81746281 is a wasteful number, since it uses less digits than its factorization.

81746281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428182.

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

The square root of 81746281 is about 9041.3649965036. The cubic root of 81746281 is about 433.9996053569. Note that the first 3 decimals are identical.

The spelling of 81746281 in words is "eighty-one million, seven hundred forty-six thousand, two hundred eighty-one".