81887542 has 16 divisors (see below), whose sum is σ = 134147664. Its totient is φ = 37180000.

The previous prime is 81887539. The next prime is 81887543. The reversal of 81887542 is 24578818.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81887543) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 27192 + ... + 30052.

It is an arithmetic number, because the mean of its divisors is an integer number (8384229).

Almost surely, 2^81887542 is an apocalyptic number.

81887542 is a deficient number, since it is larger than the sum of its proper divisors (52260122).

81887542 is a wasteful number, since it uses less digits than its factorization.

81887542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4175.

The product of its digits is 143360, while the sum is 43.

The square root of 81887542 is about 9049.1735534246. The cubic root of 81887542 is about 434.2494513338.

The spelling of 81887542 in words is "eighty-one million, eight hundred eighty-seven thousand, five hundred forty-two".