81241624464 has 480 divisors, whose sum is σ = 289810617600. Its totient is φ = 19472302080.

The previous prime is 81241624441. The next prime is 81241624507. The reversal of 81241624464 is 46442614218.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

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 95 ways as a sum of consecutive naturals, for example, 25896304 + ... + 25899440.

It is an arithmetic number, because the mean of its divisors is an integer number (603772120).

Almost surely, 2^81241624464 is an apocalyptic number.

81241624464 is a gapful number since it is divisible by the number (84) 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 81241624464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144905308800).

81241624464 is an abundant number, since it is smaller than the sum of its proper divisors (208568993136).

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

81241624464 is a wasteful number, since it uses less digits than its factorization.

81241624464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3204 (or 3173 counting only the distinct ones).

The product of its digits is 294912, while the sum is 42.

The spelling of 81241624464 in words is "eighty-one billion, two hundred forty-one million, six hundred twenty-four thousand, four hundred sixty-four".