81047481 has 8 divisors (see below), whose sum is σ = 108365760. Its totient is φ = 53880432.

The previous prime is 81047479. The next prime is 81047497. The reversal of 81047481 is 18474018.

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

It is not a de Polignac number, because 81047481 - 2¹ = 81047479 is a prime.

It is a super-2 number, since 2×81047481² = 13137388352890722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81047401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36550 + ... + 38703.

It is an arithmetic number, because the mean of its divisors is an integer number (13545720).

Almost surely, 2^81047481 is an apocalyptic number.

It is an amenable number.

81047481 is a deficient number, since it is larger than the sum of its proper divisors (27318279).

81047481 is a wasteful number, since it uses less digits than its factorization.

81047481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75615.

The product of its (nonzero) digits is 7168, while the sum is 33.

The square root of 81047481 is about 9002.6374468819. The cubic root of 81047481 is about 432.7593971116.

The spelling of 81047481 in words is "eighty-one million, forty-seven thousand, four hundred eighty-one".