81307709310 has 64 divisors (see below), whose sum is σ = 206778956544. Its totient is φ = 20390668800.

The previous prime is 81307709281. The next prime is 81307709317. The reversal of 81307709310 is 1390770318.

It is a happy number.

It is a super-2 number, since 2×81307709310² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81307709317) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 596665 + ... + 720155.

It is an arithmetic number, because the mean of its divisors is an integer number (3230921196).

Almost surely, 2^81307709310 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81307709310, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103389478272).

81307709310 is an abundant number, since it is smaller than the sum of its proper divisors (125471247234).

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

81307709310 is a wasteful number, since it uses less digits than its factorization.

81307709310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124809.

The product of its (nonzero) digits is 31752, while the sum is 39.

The spelling of 81307709310 in words is "eighty-one billion, three hundred seven million, seven hundred nine thousand, three hundred ten".