81122783 has 12 divisors (see below), whose sum is σ = 95664240. Its totient is φ = 68578272.

The previous prime is 81122779. The next prime is 81122791. The reversal of 81122783 is 38722118.

It is not a de Polignac number, because 81122783 - 2² = 81122779 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81121783) 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, 7763 + ... + 14916.

It is an arithmetic number, because the mean of its divisors is an integer number (7972020).

Almost surely, 2^81122783 is an apocalyptic number.

81122783 is a deficient number, since it is larger than the sum of its proper divisors (14541457).

81122783 is a wasteful number, since it uses less digits than its factorization.

81122783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22766 (or 22759 counting only the distinct ones).

The product of its digits is 5376, while the sum is 32.

The square root of 81122783 is about 9006.8186947446. The cubic root of 81122783 is about 432.8933826076.

The spelling of 81122783 in words is "eighty-one million, one hundred twenty-two thousand, seven hundred eighty-three".