81504783 has 24 divisors (see below), whose sum is σ = 126781200. Its totient is φ = 50267904.

The previous prime is 81504781. The next prime is 81504791. The reversal of 81504783 is 38740518.

81504783 is a `hidden beast` number, since 81 + 504 + 78 + 3 = 666.

It is a Cunningham number, because it is equal to 9028²-1.

It is not a de Polignac number, because 81504783 - 2¹ = 81504781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81504781) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4513 + ... + 13541.

It is an arithmetic number, because the mean of its divisors is an integer number (5282550).

Almost surely, 2^81504783 is an apocalyptic number.

81504783 is a deficient number, since it is larger than the sum of its proper divisors (45276417).

81504783 is a wasteful number, since it uses less digits than its factorization.

81504783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9111 (or 9108 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 81504783 is about 9027.9999446167. Note that the first 4 decimals coincide. The cubic root of 81504783 is about 433.5718043755.

The spelling of 81504783 in words is "eighty-one million, five hundred four thousand, seven hundred eighty-three".