805121672808080 has 20 divisors (see below), whose sum is σ = 1871907889278972. Its totient is φ = 322048669123200.

The previous prime is 805121672808049. The next prime is 805121672808107. The reversal of 805121672808080 is 80808276121508.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 478530850121104 + 326590822686976 = 21875348^2 + 18071824^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5032010454971 + ... + 5032010455130.

Almost surely, 2^{805121672808080} is an apocalyptic number.

805121672808080 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

805121672808080 is an abundant number, since it is smaller than the sum of its proper divisors (1066786216470892).

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

805121672808080 is a wasteful number, since it uses less digits than its factorization.

805121672808080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10064020910114 (or 10064020910108 counting only the distinct ones).

The product of its (nonzero) digits is 3440640, while the sum is 56.

The spelling of 805121672808080 in words is "eight hundred five trillion, one hundred twenty-one billion, six hundred seventy-two million, eight hundred eight thousand, eighty".