21113629 has 2 divisors, whose sum is σ = 21113630. Its totient is φ = 21113628.

The previous prime is 21113611. The next prime is 21113633. The reversal of 21113629 is 92631112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20457529 + 656100 = 4523^2 + 810^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113629 - 2⁵ = 21113597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21113639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556814 + 10556815.

It is an arithmetic number, because the mean of its divisors is an integer number (10556815).

Almost surely, 2^21113629 is an apocalyptic number.

It is an amenable number.

21113629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113629 is an equidigital number, since it uses as much as digits as its factorization.

21113629 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648, while the sum is 25.

The square root of 21113629 is about 4594.9569094824. The cubic root of 21113629 is about 276.3891320198.

The spelling of 21113629 in words is "twenty-one million, one hundred thirteen thousand, six hundred twenty-nine".