81537548 has 6 divisors (see below), whose sum is σ = 142690716. Its totient is φ = 40768772.

The previous prime is 81537517. The next prime is 81537611. The reversal of 81537548 is 84573518.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10192190 + ... + 10192197.

It is an arithmetic number, because the mean of its divisors is an integer number (23781786).

Almost surely, 2^81537548 is an apocalyptic number.

It is an amenable number.

81537548 is a deficient number, since it is larger than the sum of its proper divisors (61153168).

81537548 is a wasteful number, since it uses less digits than its factorization.

81537548 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20384391 (or 20384389 counting only the distinct ones).

The product of its digits is 134400, while the sum is 41.

The square root of 81537548 is about 9029.8143945488. The cubic root of 81537548 is about 433.6298953507.

The spelling of 81537548 in words is "eighty-one million, five hundred thirty-seven thousand, five hundred forty-eight".