81787330987 has 8 divisors (see below), whose sum is σ = 82206432000. Its totient is φ = 81368311464.

The previous prime is 81787330943. The next prime is 81787331023. The reversal of 81787330987 is 78903378718.

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

It is a cyclic number.

It is not a de Polignac number, because 81787330987 - 2²³ = 81778942379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81787330687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4013418 + ... + 4033744.

It is an arithmetic number, because the mean of its divisors is an integer number (10275804000).

Almost surely, 2^81787330987 is an apocalyptic number.

81787330987 is a deficient number, since it is larger than the sum of its proper divisors (419101013).

81787330987 is a wasteful number, since it uses less digits than its factorization.

81787330987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40745.

The product of its (nonzero) digits is 14224896, while the sum is 61.

The spelling of 81787330987 in words is "eighty-one billion, seven hundred eighty-seven million, three hundred thirty thousand, nine hundred eighty-seven".