81270400 has 96 divisors (see below), whose sum is σ = 203474700. Its totient is φ = 32071680.

The previous prime is 81270377. The next prime is 81270401. The reversal of 81270400 is 407218.

It can be written as a sum of positive squares in 6 ways, for example, as 24840256 + 56430144 = 4984^2 + 7512^2 .

It is not an unprimeable number, because it can be changed into a prime (81270401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 348684 + ... + 348916.

Almost surely, 2^81270400 is an apocalyptic number.

81270400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81270400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101737350).

81270400 is an abundant number, since it is smaller than the sum of its proper divisors (122204300).

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

81270400 is a wasteful number, since it uses less digits than its factorization.

81270400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366 (or 349 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 81270400 is about 9015.0097060403. The cubic root of 81270400 is about 433.1557984120.

Adding to 81270400 its reverse (407218), we get a palindrome (81677618).

It can be divided in two parts, 81 and 270400, that multiplied together give a square (21902400 = 4680²).

The spelling of 81270400 in words is "eighty-one million, two hundred seventy thousand, four hundred".