67991904 has 72 divisors (see below), whose sum is σ = 194234040. Its totient is φ = 22560768.

The previous prime is 67991873. The next prime is 67991909. The reversal of 67991904 is 40919976.

It is a tau number, because it is divible by the number of its divisors (72).

It is a self number, because there is not a number n which added to its sum of digits gives 67991904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67991909) 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 11 ways as a sum of consecutive naturals, for example, 88032 + ... + 88800.

It is an arithmetic number, because the mean of its divisors is an integer number (2697695).

Almost surely, 2^67991904 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 67991904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97117020).

67991904 is an abundant number, since it is smaller than the sum of its proper divisors (126242136).

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

67991904 is a wasteful number, since it uses less digits than its factorization.

67991904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1092 (or 1081 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 45.

The square root of 67991904 is about 8245.7203445181. The cubic root of 67991904 is about 408.1493109803.

The spelling of 67991904 in words is "sixty-seven million, nine hundred ninety-one thousand, nine hundred four".