144967721 has 4 divisors (see below), whose sum is σ = 153495252. Its totient is φ = 136440192.

The previous prime is 144967709. The next prime is 144967727. The reversal of 144967721 is 127769441.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 49632025 + 95335696 = 7045^2 + 9764^2 .

It is a cyclic number.

It is not a de Polignac number, because 144967721 - 2⁶ = 144967657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (144967727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4263740 + ... + 4263773.

It is an arithmetic number, because the mean of its divisors is an integer number (38373813).

Almost surely, 2^144967721 is an apocalyptic number.

It is an amenable number.

144967721 is a deficient number, since it is larger than the sum of its proper divisors (8527531).

144967721 is an equidigital number, since it uses as much as digits as its factorization.

144967721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8527530.

The product of its digits is 84672, while the sum is 41.

The square root of 144967721 is about 12040.2541916689. The cubic root of 144967721 is about 525.3198003187.

The spelling of 144967721 in words is "one hundred forty-four million, nine hundred sixty-seven thousand, seven hundred twenty-one".