21740029 has 2 divisors, whose sum is σ = 21740030. Its totient is φ = 21740028.

The previous prime is 21740027. The next prime is 21740051. The reversal of 21740029 is 92004712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13155129 + 8584900 = 3627^2 + 2930^2 .

It is a cyclic number.

It is not a de Polignac number, because 21740029 - 2¹ = 21740027 is a prime.

Together with 21740027, it forms a pair of twin primes.

It is equal to p_1373821 and since 21740029 and 1373821 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 21739985 and 21740012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21740023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10870014 + 10870015.

It is an arithmetic number, because the mean of its divisors is an integer number (10870015).

Almost surely, 2^21740029 is an apocalyptic number.

It is an amenable number.

21740029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21740029 is an equidigital number, since it uses as much as digits as its factorization.

21740029 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 21740029 is about 4662.6204005902. The cubic root of 21740029 is about 279.0958462764.

The spelling of 21740029 in words is "twenty-one million, seven hundred forty thousand, twenty-nine".