81549742 has 8 divisors (see below), whose sum is σ = 122965632. Its totient is φ = 40561200.

The previous prime is 81549737. The next prime is 81549749. The reversal of 81549742 is 24794518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 81549695 and 81549704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81549749) 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, 106359 + ... + 107122.

It is an arithmetic number, because the mean of its divisors is an integer number (15370704).

Almost surely, 2^81549742 is an apocalyptic number.

81549742 is a deficient number, since it is larger than the sum of its proper divisors (41415890).

81549742 is a wasteful number, since it uses less digits than its factorization.

81549742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213674.

The product of its digits is 80640, while the sum is 40.

The square root of 81549742 is about 9030.4895769831. The cubic root of 81549742 is about 433.6515108294.

The spelling of 81549742 in words is "eighty-one million, five hundred forty-nine thousand, seven hundred forty-two".