21001420323407 has 2 divisors, whose sum is σ = 21001420323408. Its totient is φ = 21001420323406.

The previous prime is 21001420323361. The next prime is 21001420323461. The reversal of 21001420323407 is 70432302410012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21001420323407 - 2³⁶ = 20932700846671 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21001420323407.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001420323007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500710161703 + 10500710161704.

It is an arithmetic number, because the mean of its divisors is an integer number (10500710161704).

Almost surely, 2^{21001420323407} is an apocalyptic number.

21001420323407 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001420323407 is an equidigital number, since it uses as much as digits as its factorization.

21001420323407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 29.

Adding to 21001420323407 its reverse (70432302410012), we get a palindrome (91433722733419).

The spelling of 21001420323407 in words is "twenty-one trillion, one billion, four hundred twenty million, three hundred twenty-three thousand, four hundred seven".