21144029 has 2 divisors, whose sum is σ = 21144030. Its totient is φ = 21144028.

The previous prime is 21143999. The next prime is 21144043. The reversal of 21144029 is 92044112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20232004 + 912025 = 4498^2 + 955^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21144029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21143995 and 21144013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21144049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10572014 + 10572015.

It is an arithmetic number, because the mean of its divisors is an integer number (10572015).

Almost surely, 2^21144029 is an apocalyptic number.

It is an amenable number.

21144029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21144029 is an equidigital number, since it uses as much as digits as its factorization.

21144029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 21144029 is about 4598.2636940480. The cubic root of 21144029 is about 276.5217193681.

The spelling of 21144029 in words is "twenty-one million, one hundred forty-four thousand, twenty-nine".