81153479 has 4 divisors (see below), whose sum is σ = 88531080. Its totient is φ = 73775880.

The previous prime is 81153439. The next prime is 81153481. The reversal of 81153479 is 97435118.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81153479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81153419) 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, 3688784 + ... + 3688805.

It is an arithmetic number, because the mean of its divisors is an integer number (22132770).

Almost surely, 2^81153479 is an apocalyptic number.

81153479 is a deficient number, since it is larger than the sum of its proper divisors (7377601).

81153479 is a wasteful number, since it uses less digits than its factorization.

81153479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7377600.

The product of its digits is 30240, while the sum is 38.

The square root of 81153479 is about 9008.5225758723. The cubic root of 81153479 is about 432.9479764759.

The spelling of 81153479 in words is "eighty-one million, one hundred fifty-three thousand, four hundred seventy-nine".