82120731 has 16 divisors (see below), whose sum is σ = 136512768. Its totient is φ = 42660000.

The previous prime is 82120729. The next prime is 82120739. The reversal of 82120731 is 13702128.

It is not a de Polignac number, because 82120731 - 2¹ = 82120729 is a prime.

It is a super-2 number, since 2×82120731² = 13487628919948722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (82120739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 177520 + ... + 177981.

It is an arithmetic number, because the mean of its divisors is an integer number (8532048).

Almost surely, 2^82120731 is an apocalyptic number.

82120731 is a deficient number, since it is larger than the sum of its proper divisors (54392037).

82120731 is a wasteful number, since it uses less digits than its factorization.

82120731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355522.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 82120731 is about 9062.0489404991. The cubic root of 82120731 is about 434.6612609288.

Adding to 82120731 its reverse (13702128), we get a palindrome (95822859).

The spelling of 82120731 in words is "eighty-two million, one hundred twenty thousand, seven hundred thirty-one".