81956787 has 16 divisors (see below), whose sum is σ = 119387520. Its totient is φ = 49596800.

The previous prime is 81956759. The next prime is 81956789. The reversal of 81956787 is 78765918.

It is not a de Polignac number, because 81956787 - 2¹⁰ = 81955763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81956789) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27664 + ... + 30482.

It is an arithmetic number, because the mean of its divisors is an integer number (7461720).

Almost surely, 2^81956787 is an apocalyptic number.

81956787 is a deficient number, since it is larger than the sum of its proper divisors (37430733).

81956787 is a wasteful number, since it uses less digits than its factorization.

81956787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3714.

The product of its digits is 846720, while the sum is 51.

The square root of 81956787 is about 9052.9987849331. The cubic root of 81956787 is about 434.3718188750.

The spelling of 81956787 in words is "eighty-one million, nine hundred fifty-six thousand, seven hundred eighty-seven".