81678787660 has 48 divisors (see below), whose sum is σ = 173993847552. Its totient is φ = 32201624000.

The previous prime is 81678787633. The next prime is 81678787703. The reversal of 81678787660 is 6678787618.

It is a junction number, because it is equal to n+sod(n) for n = 81678787592 and 81678787601.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6313959 + ... + 6326881.

It is an arithmetic number, because the mean of its divisors is an integer number (3624871824).

Almost surely, 2^81678787660 is an apocalyptic number.

It is an amenable number.

81678787660 is an abundant number, since it is smaller than the sum of its proper divisors (92315059892).

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

81678787660 is a wasteful number, since it uses less digits than its factorization.

81678787660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17454 (or 17452 counting only the distinct ones).

The product of its (nonzero) digits is 37933056, while the sum is 64.

The spelling of 81678787660 in words is "eighty-one billion, six hundred seventy-eight million, seven hundred eighty-seven thousand, six hundred sixty".