82661331572 has 24 divisors (see below), whose sum is σ = 146171055240. Its totient is φ = 40898304000.

The previous prime is 82661331569. The next prime is 82661331637. The reversal of 82661331572 is 27513316628.

It can be written as a sum of positive squares in 4 ways, for example, as 1044840976 + 81616490596 = 32324^2 + 285686^2 .

It is a super-2 number, since 2×82661331572² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3480554 + ... + 3504222.

It is an arithmetic number, because the mean of its divisors is an integer number (6090460635).

Almost surely, 2^82661331572 is an apocalyptic number.

It is an amenable number.

82661331572 is a deficient number, since it is larger than the sum of its proper divisors (63509723668).

82661331572 is a wasteful number, since it uses less digits than its factorization.

82661331572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32771 (or 32769 counting only the distinct ones).

The product of its digits is 362880, while the sum is 44.

The spelling of 82661331572 in words is "eighty-two billion, six hundred sixty-one million, three hundred thirty-one thousand, five hundred seventy-two".