81733877520 has 80 divisors (see below), whose sum is σ = 254426548992. Its totient is φ = 21705246720.

The previous prime is 81733877503. The next prime is 81733877543. The reversal of 81733877520 is 2577833718.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×81733877520² (a number of 23 digits) contains 22 as substring.

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, 648712 + ... + 764391.

Almost surely, 2^81733877520 is an apocalyptic number.

81733877520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81733877520 is an abundant number, since it is smaller than the sum of its proper divisors (172692671472).

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

81733877520 is a wasteful number, since it uses less digits than its factorization.

81733877520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1413360 (or 1413354 counting only the distinct ones).

The product of its (nonzero) digits is 1975680, while the sum is 51.

The spelling of 81733877520 in words is "eighty-one billion, seven hundred thirty-three million, eight hundred seventy-seven thousand, five hundred twenty".