81245719 has 2 divisors, whose sum is σ = 81245720. Its totient is φ = 81245718.

The previous prime is 81245687. The next prime is 81245743. The reversal of 81245719 is 91754218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81245719 - 2⁵ = 81245687 is a prime.

It is a super-2 number, since 2×81245719² = 13201733711653922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81245779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40622859 + 40622860.

It is an arithmetic number, because the mean of its divisors is an integer number (40622860).

Almost surely, 2^81245719 is an apocalyptic number.

81245719 is a deficient number, since it is larger than the sum of its proper divisors (1).

81245719 is an equidigital number, since it uses as much as digits as its factorization.

81245719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 37.

The square root of 81245719 is about 9013.6407183779. The cubic root of 81245719 is about 433.1119456248. Note that the first 3 decimals are identical.

The spelling of 81245719 in words is "eighty-one million, two hundred forty-five thousand, seven hundred nineteen".