81653863 has 2 divisors, whose sum is σ = 81653864. Its totient is φ = 81653862.

The previous prime is 81653833. The next prime is 81653881. The reversal of 81653863 is 36835618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81653863 - 2¹³ = 81645671 is a prime.

It is a congruent number.

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, 40826931 + 40826932.

It is an arithmetic number, because the mean of its divisors is an integer number (40826932).

Almost surely, 2^81653863 is an apocalyptic number.

81653863 is a deficient number, since it is larger than the sum of its proper divisors (1).

81653863 is an equidigital number, since it uses as much as digits as its factorization.

81653863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 40.

The square root of 81653863 is about 9036.2527078430. The cubic root of 81653863 is about 433.8359913889.

The spelling of 81653863 in words is "eighty-one million, six hundred fifty-three thousand, eight hundred sixty-three".