81436999 has 8 divisors (see below), whose sum is σ = 93664928. Its totient is φ = 69357600.

The previous prime is 81436981. The next prime is 81437009. The reversal of 81436999 is 99963418.

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 81436999 - 2⁵ = 81436967 is a prime.

It is a super-2 number, since 2×81436999² = 13263969612252002, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81436909) 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, 35952 + ... + 38149.

It is an arithmetic number, because the mean of its divisors is an integer number (11708116).

Almost surely, 2^81436999 is an apocalyptic number.

81436999 is a deficient number, since it is larger than the sum of its proper divisors (12227929).

81436999 is a wasteful number, since it uses less digits than its factorization.

81436999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74265.

The product of its digits is 419904, while the sum is 49.

The square root of 81436999 is about 9024.2450653780. The cubic root of 81436999 is about 433.4515767393.

The spelling of 81436999 in words is "eighty-one million, four hundred thirty-six thousand, nine hundred ninety-nine".