81767419 has 2 divisors, whose sum is σ = 81767420. Its totient is φ = 81767418.

The previous prime is 81767251. The next prime is 81767423. The reversal of 81767419 is 91476718.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81767419 is a prime.

It is a super-2 number, since 2×81767419² = 13371821619843122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81767459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40883709 + 40883710.

It is an arithmetic number, because the mean of its divisors is an integer number (40883710).

Almost surely, 2^81767419 is an apocalyptic number.

81767419 is a deficient number, since it is larger than the sum of its proper divisors (1).

81767419 is an equidigital number, since it uses as much as digits as its factorization.

81767419 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84672, while the sum is 43.

The square root of 81767419 is about 9042.5338816064. The cubic root of 81767419 is about 434.0370100882.

The spelling of 81767419 in words is "eighty-one million, seven hundred sixty-seven thousand, four hundred nineteen".