21429049 has 2 divisors, whose sum is σ = 21429050. Its totient is φ = 21429048.

The previous prime is 21429041. The next prime is 21429097. The reversal of 21429049 is 94092412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20839225 + 589824 = 4565^2 + 768^2 .

It is a cyclic number.

It is not a de Polignac number, because 21429049 - 2³ = 21429041 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21429049.

It is not a weakly prime, because it can be changed into another prime (21429041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10714524 + 10714525.

It is an arithmetic number, because the mean of its divisors is an integer number (10714525).

Almost surely, 2^21429049 is an apocalyptic number.

It is an amenable number.

21429049 is a deficient number, since it is larger than the sum of its proper divisors (1).

21429049 is an equidigital number, since it uses as much as digits as its factorization.

21429049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 21429049 is about 4629.1520821852. The cubic root of 21429049 is about 277.7586755516.

The spelling of 21429049 in words is "twenty-one million, four hundred twenty-nine thousand, forty-nine".