81434965 has 12 divisors (see below), whose sum is σ = 100442916. Its totient is φ = 63381888.

The previous prime is 81434921. The next prime is 81435037. The reversal of 81434965 is 56943418.

It can be written as a sum of positive squares in 6 ways, for example, as 37039396 + 44395569 = 6086^2 + 6663^2 .

It is not a de Polignac number, because 81434965 - 2⁹ = 81434453 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 897 + ... + 12793.

It is an arithmetic number, because the mean of its divisors is an integer number (8370243).

Almost surely, 2^81434965 is an apocalyptic number.

It is an amenable number.

81434965 is a deficient number, since it is larger than the sum of its proper divisors (19007951).

81434965 is a wasteful number, since it uses less digits than its factorization.

81434965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11976 (or 11939 counting only the distinct ones).

The product of its digits is 103680, while the sum is 40.

The square root of 81434965 is about 9024.1323682668. The cubic root of 81434965 is about 433.4479680280.

The spelling of 81434965 in words is "eighty-one million, four hundred thirty-four thousand, nine hundred sixty-five".