81964783 has 4 divisors (see below), whose sum is σ = 81995800. Its totient is φ = 81933768.

The previous prime is 81964777. The next prime is 81964807. The reversal of 81964783 is 38746918.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81964783 - 2¹⁷ = 81833711 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81964703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11133 + ... + 16966.

It is an arithmetic number, because the mean of its divisors is an integer number (20498950).

Almost surely, 2^81964783 is an apocalyptic number.

81964783 is a deficient number, since it is larger than the sum of its proper divisors (31017).

81964783 is a wasteful number, since it uses less digits than its factorization.

81964783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31016.

The product of its digits is 290304, while the sum is 46.

The square root of 81964783 is about 9053.4403957833. The cubic root of 81964783 is about 434.3859447098.

The spelling of 81964783 in words is "eighty-one million, nine hundred sixty-four thousand, seven hundred eighty-three".