81247801600 has 243 divisors, whose sum is σ = 234394318767. Its totient is φ = 27801661440.

The previous prime is 81247801589. The next prime is 81247801627. The reversal of 81247801600 is 610874218.

The square root of 81247801600 is 285040.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 3098480896 + 78149320704 = 55664^2 + 279552^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81247801600.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 159622146 + ... + 159622654.

Almost surely, 2^81247801600 is an apocalyptic number.

81247801600 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

81247801600 is the 285040-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81247801600

81247801600 is an abundant number, since it is smaller than the sum of its proper divisors (153146517167).

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

81247801600 is an frugal number, since it uses more digits than its factorization.

81247801600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1058 (or 523 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 37.

The spelling of 81247801600 in words is "eighty-one billion, two hundred forty-seven million, eight hundred one thousand, six hundred".