81639048530 has 32 divisors (see below), whose sum is σ = 159138302400. Its totient is φ = 29975239872.

The previous prime is 81639048529. The next prime is 81639048577. The reversal of 81639048530 is 3584093618.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1730900 + ... + 1777439.

It is an arithmetic number, because the mean of its divisors is an integer number (4973071950).

Almost surely, 2^81639048530 is an apocalyptic number.

81639048530 is a deficient number, since it is larger than the sum of its proper divisors (77499253870).

81639048530 is a wasteful number, since it uses less digits than its factorization.

81639048530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3508538.

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 81639048530 in words is "eighty-one billion, six hundred thirty-nine million, forty-eight thousand, five hundred thirty".