81430624 has 48 divisors (see below), whose sum is σ = 177342480. Its totient is φ = 36495360.

The previous prime is 81430621. The next prime is 81430693. The reversal of 81430624 is 42603418.

It is a junction number, because it is equal to n+sod(n) for n = 81430592 and 81430601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81430621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24112 + ... + 27280.

It is an arithmetic number, because the mean of its divisors is an integer number (3694635).

Almost surely, 2^81430624 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 81430624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88671240).

81430624 is an abundant number, since it is smaller than the sum of its proper divisors (95911856).

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

81430624 is a wasteful number, since it uses less digits than its factorization.

81430624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3263 (or 3255 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 81430624 is about 9023.8918433235. The cubic root of 81430624 is about 433.4402660495.

The spelling of 81430624 in words is "eighty-one million, four hundred thirty thousand, six hundred twenty-four".