81930510078 has 16 divisors (see below), whose sum is σ = 166306707840. Its totient is φ = 26902555416.

The previous prime is 81930510019. The next prime is 81930510091. The reversal of 81930510078 is 87001503918.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 101903218 + ... + 101904021.

It is an arithmetic number, because the mean of its divisors is an integer number (10394169240).

Almost surely, 2^81930510078 is an apocalyptic number.

81930510078 is an abundant number, since it is smaller than the sum of its proper divisors (84376197762).

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

81930510078 is a wasteful number, since it uses less digits than its factorization.

81930510078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203807311.

The product of its (nonzero) digits is 60480, while the sum is 42.

The spelling of 81930510078 in words is "eighty-one billion, nine hundred thirty million, five hundred ten thousand, seventy-eight".