1728068515421 has 2 divisors, whose sum is σ = 1728068515422. Its totient is φ = 1728068515420.

The previous prime is 1728068515409. The next prime is 1728068515457. The reversal of 1728068515421 is 1245158608271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1683737212921 + 44331302500 = 1297589^2 + 210550^2 .

It is a cyclic number.

It is not a de Polignac number, because 1728068515421 - 2³⁸ = 1453190608477 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1728068515421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1728068517421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 864034257710 + 864034257711.

It is an arithmetic number, because the mean of its divisors is an integer number (864034257711).

Almost surely, 2^{1728068515421} is an apocalyptic number.

It is an amenable number.

1728068515421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1728068515421 is an equidigital number, since it uses as much as digits as its factorization.

1728068515421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1075200, while the sum is 50.

The spelling of 1728068515421 in words is "one trillion, seven hundred twenty-eight billion, sixty-eight million, five hundred fifteen thousand, four hundred twenty-one".