81487428 has 48 divisors (see below), whose sum is σ = 218346240. Its totient is φ = 23392800.

The previous prime is 81487411. The next prime is 81487433. The reversal of 81487428 is 82478418.

It is a self number, because there is not a number n which added to its sum of digits gives 81487428.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 13738 + ... + 18753.

It is an arithmetic number, because the mean of its divisors is an integer number (4548880).

Almost surely, 2^81487428 is an apocalyptic number.

It is an amenable number.

81487428 is an abundant number, since it is smaller than the sum of its proper divisors (136858812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81487428 is a wasteful number, since it uses less digits than its factorization.

81487428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32528 (or 32526 counting only the distinct ones).

The product of its digits is 114688, while the sum is 42.

The square root of 81487428 is about 9027.0387170988. The cubic root of 81487428 is about 433.5410283788.

It can be divided in two parts, 8148 and 7428, that added together give a triangular number (15576 = T₁₇₆).

The spelling of 81487428 in words is "eighty-one million, four hundred eighty-seven thousand, four hundred twenty-eight".