81454531 has 4 divisors (see below), whose sum is σ = 86245992. Its totient is φ = 76663072.

The previous prime is 81454517. The next prime is 81454543. The reversal of 81454531 is 13545418.

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 81454531 - 2⁷ = 81454403 is a prime.

It is a super-2 number, since 2×81454531² = 13269681240859922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81454493 and 81454502.

It is not an unprimeable number, because it can be changed into a prime (81454561) 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, 2395705 + ... + 2395738.

It is an arithmetic number, because the mean of its divisors is an integer number (21561498).

Almost surely, 2^81454531 is an apocalyptic number.

81454531 is a deficient number, since it is larger than the sum of its proper divisors (4791461).

81454531 is a wasteful number, since it uses less digits than its factorization.

81454531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4791460.

The product of its digits is 9600, while the sum is 31.

The square root of 81454531 is about 9025.2163962977. The cubic root of 81454531 is about 433.4826794235.

Adding to 81454531 its reverse (13545418), we get a palindrome (94999949).

The spelling of 81454531 in words is "eighty-one million, four hundred fifty-four thousand, five hundred thirty-one".