81949504 has 56 divisors (see below), whose sum is σ = 200160128. Its totient is φ = 32417280.

The previous prime is 81949499. The next prime is 81949507. The reversal of 81949504 is 40594918.

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81949507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1212 + ... + 12859.

It is an arithmetic number, because the mean of its divisors is an integer number (3574288).

Almost surely, 2^81949504 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81949504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100080064).

81949504 is an abundant number, since it is smaller than the sum of its proper divisors (118210624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81949504 is a wasteful number, since it uses less digits than its factorization.

81949504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14103 (or 14093 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 81949504 is about 9052.5965335919. The cubic root of 81949504 is about 434.3589518354.

The spelling of 81949504 in words is "eighty-one million, nine hundred forty-nine thousand, five hundred four".