21264021629 has 2 divisors, whose sum is σ = 21264021630. Its totient is φ = 21264021628.

The previous prime is 21264021557. The next prime is 21264021631. The reversal of 21264021629 is 92612046212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20815852729 + 448168900 = 144277^2 + 21170^2 .

It is a cyclic number.

It is not a de Polignac number, because 21264021629 - 2²⁸ = 20995586173 is a prime.

Together with 21264021631, 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 (21264021829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10632010814 + 10632010815.

It is an arithmetic number, because the mean of its divisors is an integer number (10632010815).

Almost surely, 2^21264021629 is an apocalyptic number.

It is an amenable number.

21264021629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21264021629 is an equidigital number, since it uses as much as digits as its factorization.

21264021629 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 35.

The spelling of 21264021629 in words is "twenty-one billion, two hundred sixty-four million, twenty-one thousand, six hundred twenty-nine".