68421720 has 32 divisors (see below), whose sum is σ = 205265520. Its totient is φ = 18245760.

The previous prime is 68421713. The next prime is 68421721. The reversal of 68421720 is 2712486.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68421721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 284971 + ... + 285210.

Almost surely, 2^68421720 is an apocalyptic number.

68421720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

68421720 is an abundant number, since it is smaller than the sum of its proper divisors (136843800).

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

68421720 is a wasteful number, since it uses less digits than its factorization.

68421720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 570195 (or 570191 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 68421720 is about 8271.7422590407. The cubic root of 68421720 is about 409.0075540159.

The spelling of 68421720 in words is "sixty-eight million, four hundred twenty-one thousand, seven hundred twenty".