81469905 has 24 divisors (see below), whose sum is σ = 143282496. Its totient is φ = 39499680.

The previous prime is 81469901. The next prime is 81469909. The reversal of 81469905 is 50996418.

It is an interprime number because it is at equal distance from previous prime (81469901) and next prime (81469909).

It is not a de Polignac number, because 81469905 - 2² = 81469901 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81469901) 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 23 ways as a sum of consecutive naturals, for example, 20629 + ... + 24258.

It is an arithmetic number, because the mean of its divisors is an integer number (5970104).

Almost surely, 2^81469905 is an apocalyptic number.

It is an amenable number.

81469905 is a deficient number, since it is larger than the sum of its proper divisors (61812591).

81469905 is a wasteful number, since it uses less digits than its factorization.

81469905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44917 (or 44906 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 42.

The square root of 81469905 is about 9026.0680808423. The cubic root of 81469905 is about 433.5099500303.

The spelling of 81469905 in words is "eighty-one million, four hundred sixty-nine thousand, nine hundred five".