81538329650250 has 64 divisors (see below), whose sum is σ = 222021459084672. Its totient is φ = 19766867792000.

The previous prime is 81538329650221. The next prime is 81538329650251. The reversal of 81538329650250 is 5205692383518.

It is not an unprimeable number, because it can be changed into a prime (81538329650251) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4941708699 + ... + 4941725198.

It is an arithmetic number, because the mean of its divisors is an integer number (3469085298198).

Almost surely, 2^{81538329650250} is an apocalyptic number.

81538329650250 is an abundant number, since it is smaller than the sum of its proper divisors (140483129434422).

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

81538329650250 is a wasteful number, since it uses less digits than its factorization.

81538329650250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9883433928 (or 9883433918 counting only the distinct ones).

The product of its (nonzero) digits is 15552000, while the sum is 57.

The spelling of 81538329650250 in words is "eighty-one trillion, five hundred thirty-eight billion, three hundred twenty-nine million, six hundred fifty thousand, two hundred fifty".