68171904 has 144 divisors (see below), whose sum is σ = 211291470. Its totient is φ = 21024768.

The previous prime is 68171903. The next prime is 68171923. The reversal of 68171904 is 40917186.

It can be written as a sum of positive squares in only one way, i.e., 50126400 + 18045504 = 7080^2 + 4248^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68171903) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1155427 + ... + 1155485.

Almost surely, 2^68171904 is an apocalyptic number.

68171904 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 68171904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105645735).

68171904 is an abundant number, since it is smaller than the sum of its proper divisors (143119566).

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

68171904 is a wasteful number, since it uses less digits than its factorization.

68171904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 68171904 is about 8256.6278831009. The cubic root of 68171904 is about 408.5091682350.

The spelling of 68171904 in words is "sixty-eight million, one hundred seventy-one thousand, nine hundred four".