81453975 has 24 divisors (see below), whose sum is σ = 136016592. Its totient is φ = 43008000.

The previous prime is 81453973. The next prime is 81453989. The reversal of 81453975 is 57935418.

It is not a de Polignac number, because 81453975 - 2¹ = 81453973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81453973) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2199 + ... + 12951.

It is an arithmetic number, because the mean of its divisors is an integer number (5667358).

Almost surely, 2^81453975 is an apocalyptic number.

81453975 is a deficient number, since it is larger than the sum of its proper divisors (54562617).

81453975 is a wasteful number, since it uses less digits than its factorization.

81453975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10867 (or 10862 counting only the distinct ones).

The product of its digits is 151200, while the sum is 42.

The square root of 81453975 is about 9025.1855936596. The cubic root of 81453975 is about 433.4816931189.

It can be divided in two parts, 81453 and 975, that added together give a palindrome (82428).

The spelling of 81453975 in words is "eighty-one million, four hundred fifty-three thousand, nine hundred seventy-five".