68021520 has 160 divisors (see below), whose sum is σ = 253793280. Its totient is φ = 14722560.

The previous prime is 68021519. The next prime is 68021521. The reversal of 68021520 is 2512086.

It is an interprime number because it is at equal distance from previous prime (68021519) and next prime (68021521).

It is a super-2 number, since 2×68021520² = 9253854366220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (68021521) 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 31 ways as a sum of consecutive naturals, for example, 30855 + ... + 32985.

It is an arithmetic number, because the mean of its divisors is an integer number (1586208).

Almost surely, 2^68021520 is an apocalyptic number.

68021520 is a gapful number since it is divisible by the number (60) 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 68021520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126896640).

68021520 is an abundant number, since it is smaller than the sum of its proper divisors (185771760).

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

68021520 is a wasteful number, since it uses less digits than its factorization.

68021520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2173 (or 2167 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 68021520 is about 8247.5159896783. The cubic root of 68021520 is about 408.2085631101.

The spelling of 68021520 in words is "sixty-eight million, twenty-one thousand, five hundred twenty".