81009783 has 12 divisors (see below), whose sum is σ = 117121680. Its totient is φ = 53956896.

The previous prime is 81009763. The next prime is 81009821. The reversal of 81009783 is 38790018.

It is not a de Polignac number, because 81009783 - 2⁵ = 81009751 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81009763) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8110 + ... + 15092.

It is an arithmetic number, because the mean of its divisors is an integer number (9760140).

Almost surely, 2^81009783 is an apocalyptic number.

81009783 is a deficient number, since it is larger than the sum of its proper divisors (36111897).

81009783 is a wasteful number, since it uses less digits than its factorization.

81009783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8278 (or 8275 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 81009783 is about 9000.5434835903. The cubic root of 81009783 is about 432.6922895608.

The spelling of 81009783 in words is "eighty-one million, nine thousand, seven hundred eighty-three".