81354419 has 4 divisors (see below), whose sum is σ = 82688160. Its totient is φ = 80020680.

The previous prime is 81354407. The next prime is 81354433. The reversal of 81354419 is 91445318.

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 81354419 - 2¹² = 81350323 is a prime.

It is a super-2 number, since 2×81354419² = 13237082981655122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81354319) 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, 666779 + ... + 666900.

It is an arithmetic number, because the mean of its divisors is an integer number (20672040).

Almost surely, 2^81354419 is an apocalyptic number.

81354419 is a deficient number, since it is larger than the sum of its proper divisors (1333741).

81354419 is a wasteful number, since it uses less digits than its factorization.

81354419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1333740.

The product of its digits is 17280, while the sum is 35.

The square root of 81354419 is about 9019.6684528867. The cubic root of 81354419 is about 433.3050154408.

The spelling of 81354419 in words is "eighty-one million, three hundred fifty-four thousand, four hundred nineteen".