81239619200 has 48 divisors (see below), whose sum is σ = 200687254710. Its totient is φ = 32495846400.

The previous prime is 81239619199. The next prime is 81239619203. The reversal of 81239619200 is 291693218.

It can be written as a sum of positive squares in 3 ways, for example, as 78503073856 + 2736545344 = 280184^2 + 52312^2 .

It is a super-2 number, since 2×81239619200² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81239619203) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12690491 + ... + 12696890.

Almost surely, 2^81239619200 is an apocalyptic number.

81239619200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81239619200 is an abundant number, since it is smaller than the sum of its proper divisors (119447635510).

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

81239619200 is a wasteful number, since it uses less digits than its factorization.

81239619200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25387405 (or 25387388 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 41.

The spelling of 81239619200 in words is "eighty-one billion, two hundred thirty-nine million, six hundred nineteen thousand, two hundred".