81017949 has 8 divisors (see below), whose sum is σ = 108980352. Its totient is φ = 53533760.

The previous prime is 81017947. The next prime is 81017969. The reversal of 81017949 is 94971018.

It is a happy number.

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 81017949 - 2¹ = 81017947 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81017947) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119157 + ... + 119834.

It is an arithmetic number, because the mean of its divisors is an integer number (13622544).

Almost surely, 2^81017949 is an apocalyptic number.

It is an amenable number.

81017949 is a deficient number, since it is larger than the sum of its proper divisors (27962403).

81017949 is a wasteful number, since it uses less digits than its factorization.

81017949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239107.

The product of its (nonzero) digits is 18144, while the sum is 39.

The square root of 81017949 is about 9000.9971114316. The cubic root of 81017949 is about 432.7068279140.

The spelling of 81017949 in words is "eighty-one million, seventeen thousand, nine hundred forty-nine".