81527747 has 4 divisors (see below), whose sum is σ = 93174576. Its totient is φ = 69880920.

The previous prime is 81527707. The next prime is 81527753. The reversal of 81527747 is 74772518.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74772518 = 2 ⋅37386259.

It is a cyclic number.

It is not a de Polignac number, because 81527747 - 2⁶ = 81527683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81527707) 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, 5823404 + ... + 5823417.

It is an arithmetic number, because the mean of its divisors is an integer number (23293644).

Almost surely, 2^81527747 is an apocalyptic number.

81527747 is a deficient number, since it is larger than the sum of its proper divisors (11646829).

81527747 is a wasteful number, since it uses less digits than its factorization.

81527747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11646828.

The product of its digits is 109760, while the sum is 41.

The square root of 81527747 is about 9029.2716760545. The cubic root of 81527747 is about 433.6125202191.

The spelling of 81527747 in words is "eighty-one million, five hundred twenty-seven thousand, seven hundred forty-seven".