21425399207767 has 2 divisors, whose sum is σ = 21425399207768. Its totient is φ = 21425399207766.

The previous prime is 21425399207731. The next prime is 21425399207789. The reversal of 21425399207767 is 76770299352412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21425399207767 - 2¹¹ = 21425399205719 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21425399207699 and 21425399207708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21425399207167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712699603883 + 10712699603884.

It is an arithmetic number, because the mean of its divisors is an integer number (10712699603884).

Almost surely, 2^{21425399207767} is an apocalyptic number.

21425399207767 is a deficient number, since it is larger than the sum of its proper divisors (1).

21425399207767 is an equidigital number, since it uses as much as digits as its factorization.

21425399207767 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80015040, while the sum is 64.

The spelling of 21425399207767 in words is "twenty-one trillion, four hundred twenty-five billion, three hundred ninety-nine million, two hundred seven thousand, seven hundred sixty-seven".