81235997 has 8 divisors (see below), whose sum is σ = 82280640. Its totient is φ = 80196480.

The previous prime is 81235993. The next prime is 81236003. The reversal of 81235997 is 79953218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81235997 - 2² = 81235993 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81235991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37997 + ... + 40077.

It is an arithmetic number, because the mean of its divisors is an integer number (10285080).

Almost surely, 2^81235997 is an apocalyptic number.

It is an amenable number.

81235997 is a deficient number, since it is larger than the sum of its proper divisors (1044643).

81235997 is a wasteful number, since it uses less digits than its factorization.

81235997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2563.

The product of its digits is 136080, while the sum is 44.

The square root of 81235997 is about 9013.1014085053. The cubic root of 81235997 is about 433.0946693000.

The spelling of 81235997 in words is "eighty-one million, two hundred thirty-five thousand, nine hundred ninety-seven".