144840721 has 2 divisors, whose sum is σ = 144840722. Its totient is φ = 144840720.

The previous prime is 144840719. The next prime is 144840737. The reversal of 144840721 is 127048441.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141729025 + 3111696 = 11905^2 + 1764^2 .

It is a cyclic number.

It is not a de Polignac number, because 144840721 - 2¹ = 144840719 is a prime.

Together with 144840719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (144840701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72420360 + 72420361.

It is an arithmetic number, because the mean of its divisors is an integer number (72420361).

Almost surely, 2^144840721 is an apocalyptic number.

It is an amenable number.

144840721 is a deficient number, since it is larger than the sum of its proper divisors (1).

144840721 is an equidigital number, since it uses as much as digits as its factorization.

144840721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 144840721 is about 12034.9790610537. The cubic root of 144840721 is about 525.1663521214.

The spelling of 144840721 in words is "one hundred forty-four million, eight hundred forty thousand, seven hundred twenty-one".