81235019 has 2 divisors, whose sum is σ = 81235020. Its totient is φ = 81235018.

The previous prime is 81234997. The next prime is 81235031. The reversal of 81235019 is 91053218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81235019 - 2⁸ = 81234763 is a prime.

It is a super-2 number, since 2×81235019² = 13198256623860722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81234982 and 81235000.

It is not a weakly prime, because it can be changed into another prime (81235069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40617509 + 40617510.

It is an arithmetic number, because the mean of its divisors is an integer number (40617510).

Almost surely, 2^81235019 is an apocalyptic number.

81235019 is a deficient number, since it is larger than the sum of its proper divisors (1).

81235019 is an equidigital number, since it uses as much as digits as its factorization.

81235019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 81235019 is about 9013.0471539874. The cubic root of 81235019 is about 433.0929312844.

The spelling of 81235019 in words is "eighty-one million, two hundred thirty-five thousand, nineteen".