81562331400 has 576 divisors, whose sum is σ = 298236893760. Its totient is φ = 18278400000.

The previous prime is 81562331351. The next prime is 81562331471. The reversal of 81562331400 is 413326518.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 116351050 + ... + 116351750.

It is an arithmetic number, because the mean of its divisors is an integer number (517772385).

Almost surely, 2^81562331400 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81562331400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149118446880).

81562331400 is an abundant number, since it is smaller than the sum of its proper divisors (216674562360).

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

81562331400 is a wasteful number, since it uses less digits than its factorization.

81562331400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826 (or 800 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

Adding to 81562331400 its reverse (413326518), we get a palindrome (81975657918).

The spelling of 81562331400 in words is "eighty-one billion, five hundred sixty-two million, three hundred thirty-one thousand, four hundred".