21211020407 has 2 divisors, whose sum is σ = 21211020408. Its totient is φ = 21211020406.

The previous prime is 21211020359. The next prime is 21211020421. The reversal of 21211020407 is 70402011212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21211020407 - 2¹⁶ = 21210954871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211020427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605510203 + 10605510204.

It is an arithmetic number, because the mean of its divisors is an integer number (10605510204).

Almost surely, 2^21211020407 is an apocalyptic number.

21211020407 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211020407 is an equidigital number, since it uses as much as digits as its factorization.

21211020407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 20.

Adding to 21211020407 its reverse (70402011212), we get a palindrome (91613031619).

The spelling of 21211020407 in words is "twenty-one billion, two hundred eleven million, twenty thousand, four hundred seven".