81741951 has 6 divisors (see below), whose sum is σ = 118071720. Its totient is φ = 54494628.

The previous prime is 81741949. The next prime is 81741973. The reversal of 81741951 is 15914718.

It is not a de Polignac number, because 81741951 - 2¹ = 81741949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81741911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4541211 + ... + 4541228.

It is an arithmetic number, because the mean of its divisors is an integer number (19678620).

Almost surely, 2^81741951 is an apocalyptic number.

81741951 is a deficient number, since it is larger than the sum of its proper divisors (36329769).

81741951 is a wasteful number, since it uses less digits than its factorization.

81741951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9082445 (or 9082442 counting only the distinct ones).

The product of its digits is 10080, while the sum is 36.

The square root of 81741951 is about 9041.1255383387. The cubic root of 81741951 is about 433.9919424131.

The spelling of 81741951 in words is "eighty-one million, seven hundred forty-one thousand, nine hundred fifty-one".