81874519 has 2 divisors, whose sum is σ = 81874520. Its totient is φ = 81874518.

The previous prime is 81874493. The next prime is 81874523. The reversal of 81874519 is 91547818.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81874519 - 2¹³ = 81866327 is a prime.

It is a super-2 number, since 2×81874519² = 13406873722962722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81874019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40937259 + 40937260.

It is an arithmetic number, because the mean of its divisors is an integer number (40937260).

Almost surely, 2^81874519 is an apocalyptic number.

81874519 is a deficient number, since it is larger than the sum of its proper divisors (1).

81874519 is an equidigital number, since it uses as much as digits as its factorization.

81874519 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 43.

The square root of 81874519 is about 9048.4539563397. The cubic root of 81874519 is about 434.2264298001.

The spelling of 81874519 in words is "eighty-one million, eight hundred seventy-four thousand, five hundred nineteen".