81554400 has 216 divisors, whose sum is σ = 294918624. Its totient is φ = 21196800.

The previous prime is 81554387. The next prime is 81554411. The reversal of 81554400 is 445518.

It is a super-2 number, since 2×81554400² = 13302240318720000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 338280 + ... + 338520.

It is an arithmetic number, because the mean of its divisors is an integer number (1365364).

Almost surely, 2^81554400 is an apocalyptic number.

81554400 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 81554400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147459312).

81554400 is an abundant number, since it is smaller than the sum of its proper divisors (213364224).

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

81554400 is a wasteful number, since it uses less digits than its factorization.

81554400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314 (or 298 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 81554400 is about 9030.7474773686. The cubic root of 81554400 is about 433.6597671820.

Adding to 81554400 its reverse (445518), we get a palindrome (81999918).

The spelling of 81554400 in words is "eighty-one million, five hundred fifty-four thousand, four hundred".