21001420323461 has 2 divisors, whose sum is σ = 21001420323462. Its totient is φ = 21001420323460.

The previous prime is 21001420323407. The next prime is 21001420323463. The reversal of 21001420323461 is 16432302410012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20070677760961 + 930742562500 = 4480031^2 + 964750^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001420323461 - 2²² = 21001416129157 is a prime.

Together with 21001420323463, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001420323463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500710161730 + 10500710161731.

It is an arithmetic number, because the mean of its divisors is an integer number (10500710161731).

Almost surely, 2^{21001420323461} is an apocalyptic number.

It is an amenable number.

21001420323461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001420323461 is an equidigital number, since it uses as much as digits as its factorization.

21001420323461 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 29.

Adding to 21001420323461 its reverse (16432302410012), we get a palindrome (37433722733473).

The spelling of 21001420323461 in words is "twenty-one trillion, one billion, four hundred twenty million, three hundred twenty-three thousand, four hundred sixty-one".