81739542 has 8 divisors (see below), whose sum is σ = 163479096. Its totient is φ = 27246512.

The previous prime is 81739513. The next prime is 81739571. The reversal of 81739542 is 24593718.

It is an interprime number because it is at equal distance from previous prime (81739513) and next prime (81739571).

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

81739542 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 81739542.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 6811623 + ... + 6811634.

It is an arithmetic number, because the mean of its divisors is an integer number (20434887).

Almost surely, 2^81739542 is an apocalyptic number.

81739542 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81739542 is a wasteful number, since it uses less digits than its factorization.

81739542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13623262.

The product of its digits is 60480, while the sum is 39.

The square root of 81739542 is about 9040.9923127940. The cubic root of 81739542 is about 433.9876790092.

The spelling of 81739542 in words is "eighty-one million, seven hundred thirty-nine thousand, five hundred forty-two".