81240053200 has 60 divisors (see below), whose sum is σ = 195216259948. Its totient is φ = 32489856000.

The previous prime is 81240053189. The next prime is 81240053261. The reversal of 81240053200 is 235004218.

It can be written as a sum of positive squares in 6 ways, for example, as 124456336 + 81115596864 = 11156^2 + 284808^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2504284 + ... + 2536516.

Almost surely, 2^81240053200 is an apocalyptic number.

81240053200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81240053200 is an abundant number, since it is smaller than the sum of its proper divisors (113976206748).

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

81240053200 is a wasteful number, since it uses less digits than its factorization.

81240053200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38552 (or 38541 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 81240053200 its reverse (235004218), we get a palindrome (81475057418).

The spelling of 81240053200 in words is "eighty-one billion, two hundred forty million, fifty-three thousand, two hundred".