81528709955624 has 64 divisors (see below), whose sum is σ = 158424638400000. Its totient is φ = 39287262163968.

The previous prime is 81528709955591. The next prime is 81528709955701. The reversal of 81528709955624 is 42655990782518.

It is a Cunningham number, because it is equal to 9029325²-1.

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, 1047362897 + ... + 1047440735.

It is an arithmetic number, because the mean of its divisors is an integer number (2475384975000).

Almost surely, 2^{81528709955624} is an apocalyptic number.

It is an amenable number.

81528709955624 is a deficient number, since it is larger than the sum of its proper divisors (76895928444376).

81528709955624 is a wasteful number, since it uses less digits than its factorization.

81528709955624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86010 (or 86006 counting only the distinct ones).

The product of its (nonzero) digits is 435456000, while the sum is 71.

The spelling of 81528709955624 in words is "eighty-one trillion, five hundred twenty-eight billion, seven hundred nine million, nine hundred fifty-five thousand, six hundred twenty-four".