1440398021 has 2 divisors, whose sum is σ = 1440398022. Its totient is φ = 1440398020.

The previous prime is 1440398017. The next prime is 1440398039. The reversal of 1440398021 is 1208930441.

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., 1275275521 + 165122500 = 35711^2 + 12850^2 .

It is a cyclic number.

It is not a de Polignac number, because 1440398021 - 2² = 1440398017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1440398051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 720199010 + 720199011.

It is an arithmetic number, because the mean of its divisors is an integer number (720199011).

Almost surely, 2^1440398021 is an apocalyptic number.

It is an amenable number.

1440398021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1440398021 is an equidigital number, since it uses as much as digits as its factorization.

1440398021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1440398021 is about 37952.5759468313. The cubic root of 1440398021 is about 1129.3472673232.

The spelling of 1440398021 in words is "one billion, four hundred forty million, three hundred ninety-eight thousand, twenty-one".