81201248400 has 60 divisors (see below), whose sum is σ = 260114669552. Its totient is φ = 21653665920.

The previous prime is 81201248393. The next prime is 81201248407. The reversal of 81201248400 is 484210218.

It is an interprime number because it is at equal distance from previous prime (81201248393) and next prime (81201248407).

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (81201248407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33832654 + ... + 33835053.

Almost surely, 2^81201248400 is an apocalyptic number.

81201248400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81201248400 is an abundant number, since it is smaller than the sum of its proper divisors (178913421152).

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

81201248400 is a wasteful number, since it uses less digits than its factorization.

81201248400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67667728 (or 67667717 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 30.

Adding to 81201248400 its reverse (484210218), we get a palindrome (81685458618).

The spelling of 81201248400 in words is "eighty-one billion, two hundred one million, two hundred forty-eight thousand, four hundred".