21425399207801 has 2 divisors, whose sum is σ = 21425399207802. Its totient is φ = 21425399207800.

The previous prime is 21425399207789. The next prime is 21425399207827. The reversal of 21425399207801 is 10870299352412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18353932654201 + 3071466553600 = 4284149^2 + 1752560^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21425399207801 is a prime.

It is not a weakly prime, because it can be changed into another prime (21425399207501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712699603900 + 10712699603901.

It is an arithmetic number, because the mean of its divisors is an integer number (10712699603901).

Almost surely, 2^{21425399207801} is an apocalyptic number.

It is an amenable number.

21425399207801 is a deficient number, since it is larger than the sum of its proper divisors (1).

21425399207801 is an equidigital number, since it uses as much as digits as its factorization.

21425399207801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2177280, while the sum is 53.

The spelling of 21425399207801 in words is "twenty-one trillion, four hundred twenty-five billion, three hundred ninety-nine million, two hundred seven thousand, eight hundred one".