81247741 has 4 divisors (see below), whose sum is σ = 81283392. Its totient is φ = 81212092.

The previous prime is 81247721. The next prime is 81247757. The reversal of 81247741 is 14774218.

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, and also an emirpimes, since its reverse is a distinct semiprime: 14774218 = 2 ⋅7387109.

It is a cyclic number.

It is not a de Polignac number, because 81247741 - 2¹⁷ = 81116669 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81247697 and 81247706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81247721) 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, 14155 + ... + 19048.

It is an arithmetic number, because the mean of its divisors is an integer number (20320848).

Almost surely, 2^81247741 is an apocalyptic number.

It is an amenable number.

81247741 is a deficient number, since it is larger than the sum of its proper divisors (35651).

81247741 is a wasteful number, since it uses less digits than its factorization.

81247741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35650.

The product of its digits is 12544, while the sum is 34.

The square root of 81247741 is about 9013.7528810147. The cubic root of 81247741 is about 433.1155386145.

The spelling of 81247741 in words is "eighty-one million, two hundred forty-seven thousand, seven hundred forty-one".