81311342630 has 64 divisors (see below), whose sum is σ = 171601016832. Its totient is φ = 27164730240.

The previous prime is 81311342627. The next prime is 81311342677. The reversal of 81311342630 is 3624311318.

It is a super-2 number, since 2×81311342630² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 367907 + ... + 545873.

It is an arithmetic number, because the mean of its divisors is an integer number (2681265888).

Almost surely, 2^81311342630 is an apocalyptic number.

81311342630 is an abundant number, since it is smaller than the sum of its proper divisors (90289674202).

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

81311342630 is a wasteful number, since it uses less digits than its factorization.

81311342630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178149.

The product of its (nonzero) digits is 10368, while the sum is 32.

Adding to 81311342630 its reverse (3624311318), we get a palindrome (84935653948).

The spelling of 81311342630 in words is "eighty-one billion, three hundred eleven million, three hundred forty-two thousand, six hundred thirty".