81729295 has 4 divisors (see below), whose sum is σ = 98075160. Its totient is φ = 65383432.

The previous prime is 81729293. The next prime is 81729311. The reversal of 81729295 is 59292718.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 59292718 = 2 ⋅29646359.

It is a cyclic number.

It is not a de Polignac number, because 81729295 - 2¹ = 81729293 is a prime.

It is a super-2 number, since 2×81729295² = 13359355322394050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81729293) 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, 8172925 + ... + 8172934.

It is an arithmetic number, because the mean of its divisors is an integer number (24518790).

Almost surely, 2^81729295 is an apocalyptic number.

81729295 is a deficient number, since it is larger than the sum of its proper divisors (16345865).

81729295 is a wasteful number, since it uses less digits than its factorization.

81729295 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16345864.

The product of its digits is 90720, while the sum is 43.

The square root of 81729295 is about 9040.4255983886. The cubic root of 81729295 is about 433.9695431209.

The spelling of 81729295 in words is "eighty-one million, seven hundred twenty-nine thousand, two hundred ninety-five".