21025019259017 has 2 divisors, whose sum is σ = 21025019259018. Its totient is φ = 21025019259016.

The previous prime is 21025019258977. The next prime is 21025019259043. The reversal of 21025019259017 is 71095291052012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20733050862736 + 291968396281 = 4553356^2 + 540341^2 .

It is a cyclic number.

It is not a de Polignac number, because 21025019259017 - 2⁶ = 21025019258953 is a prime.

It is not a weakly prime, because it can be changed into another prime (21025019259917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10512509629508 + 10512509629509.

It is an arithmetic number, because the mean of its divisors is an integer number (10512509629509).

Almost surely, 2^{21025019259017} is an apocalyptic number.

It is an amenable number.

21025019259017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21025019259017 is an equidigital number, since it uses as much as digits as its factorization.

21025019259017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 113400, while the sum is 44.

The spelling of 21025019259017 in words is "twenty-one trillion, twenty-five billion, nineteen million, two hundred fifty-nine thousand, seventeen".