81817454 has 4 divisors (see below), whose sum is σ = 122726184. Its totient is φ = 40908726.

The previous prime is 81817453. The next prime is 81817487. The reversal of 81817454 is 45471818.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81817453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20454362 + ... + 20454365.

It is an arithmetic number, because the mean of its divisors is an integer number (30681546).

Almost surely, 2^81817454 is an apocalyptic number.

81817454 is a deficient number, since it is larger than the sum of its proper divisors (40908730).

81817454 is a wasteful number, since it uses less digits than its factorization.

81817454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40908729.

The product of its digits is 35840, while the sum is 38.

The square root of 81817454 is about 9045.3001055797. The cubic root of 81817454 is about 434.1255238014.

The spelling of 81817454 in words is "eighty-one million, eight hundred seventeen thousand, four hundred fifty-four".