21536629 has 2 divisors, whose sum is σ = 21536630. Its totient is φ = 21536628.

The previous prime is 21536623. The next prime is 21536657. The reversal of 21536629 is 92663512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10824100 + 10712529 = 3290^2 + 3273^2 .

It is a cyclic number.

It is not a de Polignac number, because 21536629 - 2³ = 21536621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21536594 and 21536603.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21536621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10768314 + 10768315.

It is an arithmetic number, because the mean of its divisors is an integer number (10768315).

Almost surely, 2^21536629 is an apocalyptic number.

It is an amenable number.

21536629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21536629 is an equidigital number, since it uses as much as digits as its factorization.

21536629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 34.

The square root of 21536629 is about 4640.7573735329. The cubic root of 21536629 is about 278.2227094137. Note that the first 3 decimals are identical.

The spelling of 21536629 in words is "twenty-one million, five hundred thirty-six thousand, six hundred twenty-nine".