21047629 has 2 divisors, whose sum is σ = 21047630. Its totient is φ = 21047628.

The previous prime is 21047617. The next prime is 21047647. The reversal of 21047629 is 92674012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14235529 + 6812100 = 3773^2 + 2610^2 .

It is a cyclic number.

It is not a de Polignac number, because 21047629 - 2¹⁷ = 20916557 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21047629.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21047669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10523814 + 10523815.

It is an arithmetic number, because the mean of its divisors is an integer number (10523815).

Almost surely, 2^21047629 is an apocalyptic number.

It is an amenable number.

21047629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21047629 is an equidigital number, since it uses as much as digits as its factorization.

21047629 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 21047629 is about 4587.7695016206. The cubic root of 21047629 is about 276.1008391944.

The spelling of 21047629 in words is "twenty-one million, forty-seven thousand, six hundred twenty-nine".