82161608121 has 20 divisors (see below), whose sum is σ = 122743222800. Its totient is φ = 54770843736.

The previous prime is 82161608117. The next prime is 82161608131. The reversal of 82161608121 is 12180616128.

82161608121 is a `hidden beast` number, since 8 + 21 + 6 + 1 + 608 + 1 + 21 = 666.

It is not a de Polignac number, because 82161608121 - 2² = 82161608117 is a prime.

It is not an unprimeable number, because it can be changed into a prime (82161608131) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1957170 + ... + 1998708.

It is an arithmetic number, because the mean of its divisors is an integer number (6137161140).

Almost surely, 2^82161608121 is an apocalyptic number.

82161608121 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

82161608121 is a deficient number, since it is larger than the sum of its proper divisors (40581614679).

82161608121 is a wasteful number, since it uses less digits than its factorization.

82161608121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65970 (or 65961 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The spelling of 82161608121 in words is "eighty-two billion, one hundred sixty-one million, six hundred eight thousand, one hundred twenty-one".