81457741 has 4 divisors (see below), whose sum is σ = 81489852. Its totient is φ = 81425632.

The previous prime is 81457711. The next prime is 81457799. The reversal of 81457741 is 14775418.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39012516 + 42445225 = 6246^2 + 6515^2 .

It is a cyclic number.

It is not a de Polignac number, because 81457741 - 2⁷ = 81457613 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 81457741.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81457711) 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, 11890 + ... + 17443.

It is an arithmetic number, because the mean of its divisors is an integer number (20372463).

Almost surely, 2^81457741 is an apocalyptic number.

It is an amenable number.

81457741 is a deficient number, since it is larger than the sum of its proper divisors (32111).

81457741 is a wasteful number, since it uses less digits than its factorization.

81457741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32110.

The product of its digits is 31360, while the sum is 37.

The square root of 81457741 is about 9025.3942296168. The cubic root of 81457741 is about 433.4883736478.

The spelling of 81457741 in words is "eighty-one million, four hundred fifty-seven thousand, seven hundred forty-one".