21226021507 has 2 divisors, whose sum is σ = 21226021508. Its totient is φ = 21226021506.

The previous prime is 21226021493. The next prime is 21226021541. The reversal of 21226021507 is 70512062212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21226021507 is a prime.

It is not a weakly prime, because it can be changed into another prime (21226021567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10613010753 + 10613010754.

It is an arithmetic number, because the mean of its divisors is an integer number (10613010754).

Almost surely, 2^21226021507 is an apocalyptic number.

21226021507 is a deficient number, since it is larger than the sum of its proper divisors (1).

21226021507 is an equidigital number, since it uses as much as digits as its factorization.

21226021507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 28.

Adding to 21226021507 its reverse (70512062212), we get a palindrome (91738083719).

The spelling of 21226021507 in words is "twenty-one billion, two hundred twenty-six million, twenty-one thousand, five hundred seven".