144721728 has 70 divisors (see below), whose sum is σ = 429015906. Its totient is φ = 48238848.

The previous prime is 144721721. The next prime is 144721729. The reversal of 144721728 is 827127441.

144721728 is a `hidden beast` number, since 14 + 472 + 172 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 142850304 + 1871424 = 11952^2 + 1368^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 144721692 and 144721701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (144721721) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 8775 + ... + 19142.

Almost surely, 2^144721728 is an apocalyptic number.

144721728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

144721728 is an abundant number, since it is smaller than the sum of its proper divisors (284294178).

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

144721728 is an equidigital number, since it uses as much as digits as its factorization.

144721728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27941 (or 27922 counting only the distinct ones).

The product of its digits is 25088, while the sum is 36.

The square root of 144721728 is about 12030.0344139159. The cubic root of 144721728 is about 525.0224969951.

The spelling of 144721728 in words is "one hundred forty-four million, seven hundred twenty-one thousand, seven hundred twenty-eight".