81455419 has 4 divisors (see below), whose sum is σ = 81943344. Its totient is φ = 80967496.

The previous prime is 81455417. The next prime is 81455431. The reversal of 81455419 is 91455418.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81455419 - 2¹ = 81455417 is a prime.

It is a super-2 number, since 2×81455419² = 13269970568931122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81455417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243712 + ... + 244045.

It is an arithmetic number, because the mean of its divisors is an integer number (20485836).

Almost surely, 2^81455419 is an apocalyptic number.

81455419 is a deficient number, since it is larger than the sum of its proper divisors (487925).

81455419 is a wasteful number, since it uses less digits than its factorization.

81455419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487924.

The product of its digits is 28800, while the sum is 37.

The square root of 81455419 is about 9025.2655916599. The cubic root of 81455419 is about 433.4842546631.

Subtracting 81455419 from its reverse (91455418), we obtain a palindrome (9999999).

The spelling of 81455419 in words is "eighty-one million, four hundred fifty-five thousand, four hundred nineteen".