82181631 has 32 divisors (see below), whose sum is σ = 134092800. Its totient is φ = 43722720.

The previous prime is 82181591. The next prime is 82181633. The reversal of 82181631 is 13618128.

It is not a de Polignac number, because 82181631 - 2¹⁰ = 82180607 is a prime.

It is a super-2 number, since 2×82181631² = 13507640947640322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82181633) 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, 21796 + ... + 25286.

It is an arithmetic number, because the mean of its divisors is an integer number (4190400).

Almost surely, 2^82181631 is an apocalyptic number.

82181631 is a deficient number, since it is larger than the sum of its proper divisors (51911169).

82181631 is a wasteful number, since it uses less digits than its factorization.

82181631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3579.

The product of its digits is 2304, while the sum is 30.

The square root of 82181631 is about 9065.4084850050. The cubic root of 82181631 is about 434.7686813476.

Adding to 82181631 its reverse (13618128), we get a palindrome (95799759).

The spelling of 82181631 in words is "eighty-two million, one hundred eighty-one thousand, six hundred thirty-one".