81616089534 has 16 divisors (see below), whose sum is σ = 186551061888. Its totient is φ = 23318882712.

The previous prime is 81616089517. The next prime is 81616089547. The reversal of 81616089534 is 43598061618.

It is a super-2 number, since 2×81616089534² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 971620072 + ... + 971620155.

It is an arithmetic number, because the mean of its divisors is an integer number (11659441368).

Almost surely, 2^81616089534 is an apocalyptic number.

81616089534 is an abundant number, since it is smaller than the sum of its proper divisors (104934972354).

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

81616089534 is a wasteful number, since it uses less digits than its factorization.

81616089534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1943240239.

The product of its (nonzero) digits is 1244160, while the sum is 51.

The spelling of 81616089534 in words is "eighty-one billion, six hundred sixteen million, eighty-nine thousand, five hundred thirty-four".