81150747 has 4 divisors (see below), whose sum is σ = 108201000. Its totient is φ = 54100496.

The previous prime is 81150737. The next prime is 81150749. The reversal of 81150747 is 74705118.

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

It is a cyclic number.

It is not a de Polignac number, because 81150747 - 2¹⁶ = 81085211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81150749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13525122 + ... + 13525127.

It is an arithmetic number, because the mean of its divisors is an integer number (27050250).

Almost surely, 2^81150747 is an apocalyptic number.

81150747 is a deficient number, since it is larger than the sum of its proper divisors (27050253).

81150747 is a wasteful number, since it uses less digits than its factorization.

81150747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27050252.

The product of its (nonzero) digits is 7840, while the sum is 33.

The square root of 81150747 is about 9008.3709404087. The cubic root of 81150747 is about 432.9431180802.

The spelling of 81150747 in words is "eighty-one million, one hundred fifty thousand, seven hundred forty-seven".