81687407288 has 16 divisors (see below), whose sum is σ = 153172572360. Its totient is φ = 40841388000.

The previous prime is 81687407279. The next prime is 81687407299. The reversal of 81687407288 is 88270478618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134663 + ... + 426038.

Almost surely, 2^81687407288 is an apocalyptic number.

It is an amenable number.

81687407288 is a deficient number, since it is larger than the sum of its proper divisors (71485165072).

81687407288 is a wasteful number, since it uses less digits than its factorization.

81687407288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578918 (or 578914 counting only the distinct ones).

The product of its (nonzero) digits is 9633792, while the sum is 59.

The spelling of 81687407288 in words is "eighty-one billion, six hundred eighty-seven million, four hundred seven thousand, two hundred eighty-eight".