81500434420 has 48 divisors (see below), whose sum is σ = 175174610688. Its totient is φ = 31834131840.

The previous prime is 81500434399. The next prime is 81500434423. The reversal of 81500434420 is 2443400518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81500434423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4434450 + ... + 4452790.

It is an arithmetic number, because the mean of its divisors is an integer number (3649471056).

Almost surely, 2^81500434420 is an apocalyptic number.

It is an amenable number.

81500434420 is an abundant number, since it is smaller than the sum of its proper divisors (93674176268).

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

81500434420 is a wasteful number, since it uses less digits than its factorization.

81500434420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23560 (or 23558 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 31.

Adding to 81500434420 its reverse (2443400518), we get a palindrome (83943834938).

The spelling of 81500434420 in words is "eighty-one billion, five hundred million, four hundred thirty-four thousand, four hundred twenty".