21421223207 has 2 divisors, whose sum is σ = 21421223208. Its totient is φ = 21421223206.

The previous prime is 21421223123. The next prime is 21421223209. The reversal of 21421223207 is 70232212412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21421223207 - 2¹⁴ = 21421206823 is a prime.

Together with 21421223209, 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 (21421223209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710611603 + 10710611604.

It is an arithmetic number, because the mean of its divisors is an integer number (10710611604).

Almost surely, 2^21421223207 is an apocalyptic number.

21421223207 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421223207 is an equidigital number, since it uses as much as digits as its factorization.

21421223207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 26.

Adding to 21421223207 its reverse (70232212412), we get a palindrome (91653435619).

The spelling of 21421223207 in words is "twenty-one billion, four hundred twenty-one million, two hundred twenty-three thousand, two hundred seven".