68400520 has 96 divisors (see below), whose sum is σ = 167879880. Its totient is φ = 25067520.

The previous prime is 68400511. The next prime is 68400523. The reversal of 68400520 is 2500486.

It can be written as a sum of positive squares in 12 ways, for example, as 5579044 + 62821476 = 2362^2 + 7926^2 .

It is a super-2 number, since 2×68400520² = 9357262272540800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (68400523) 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 23 ways as a sum of consecutive naturals, for example, 705112 + ... + 705208.

Almost surely, 2^68400520 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 68400520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83939940).

68400520 is an abundant number, since it is smaller than the sum of its proper divisors (99479360).

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

68400520 is a wasteful number, since it uses less digits than its factorization.

68400520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203 (or 182 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 68400520 is about 8270.4606884986. The cubic root of 68400520 is about 408.9653069251.

The spelling of 68400520 in words is "sixty-eight million, four hundred thousand, five hundred twenty".