81280061 has 4 divisors (see below), whose sum is σ = 83009472. Its totient is φ = 79550652.

The previous prime is 81280049. The next prime is 81280079. The reversal of 81280061 is 16008218.

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 81280061 - 2¹⁸ = 81017917 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 81280061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81280261) 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, 864635 + ... + 864728.

It is an arithmetic number, because the mean of its divisors is an integer number (20752368).

Almost surely, 2^81280061 is an apocalyptic number.

It is an amenable number.

81280061 is a deficient number, since it is larger than the sum of its proper divisors (1729411).

81280061 is a wasteful number, since it uses less digits than its factorization.

81280061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1729410.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 81280061 is about 9015.5455187138. The cubic root of 81280061 is about 433.1729614970.

Adding to 81280061 its reverse (16008218), we get a palindrome (97288279).

The spelling of 81280061 in words is "eighty-one million, two hundred eighty thousand, sixty-one".