81653833 has 2 divisors, whose sum is σ = 81653834. Its totient is φ = 81653832.

The previous prime is 81653827. The next prime is 81653863. The reversal of 81653833 is 33835618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76510009 + 5143824 = 8747^2 + 2268^2 .

It is a cyclic number.

It is not a de Polignac number, because 81653833 - 2⁵ = 81653801 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81653792 and 81653801.

It is not a weakly prime, because it can be changed into another prime (81653813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40826916 + 40826917.

It is an arithmetic number, because the mean of its divisors is an integer number (40826917).

Almost surely, 2^81653833 is an apocalyptic number.

It is an amenable number.

81653833 is a deficient number, since it is larger than the sum of its proper divisors (1).

81653833 is an equidigital number, since it uses as much as digits as its factorization.

81653833 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 37.

The square root of 81653833 is about 9036.2510478627. The cubic root of 81653833 is about 433.8359382578.

The spelling of 81653833 in words is "eighty-one million, six hundred fifty-three thousand, eight hundred thirty-three".