21355466420399 has 2 divisors, whose sum is σ = 21355466420400. Its totient is φ = 21355466420398.

The previous prime is 21355466420371. The next prime is 21355466420429. The reversal of 21355466420399 is 99302466455312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21355466420399 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21355466420339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10677733210199 + 10677733210200.

It is an arithmetic number, because the mean of its divisors is an integer number (10677733210200).

Almost surely, 2^{21355466420399} is an apocalyptic number.

21355466420399 is a deficient number, since it is larger than the sum of its proper divisors (1).

21355466420399 is an equidigital number, since it uses as much as digits as its factorization.

21355466420399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41990400, while the sum is 59.

The spelling of 21355466420399 in words is "twenty-one trillion, three hundred fifty-five billion, four hundred sixty-six million, four hundred twenty thousand, three hundred ninety-nine".