21853129 has 2 divisors, whose sum is σ = 21853130. Its totient is φ = 21853128.

The previous prime is 21853121. The next prime is 21853141. The reversal of 21853129 is 92135812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14235529 + 7617600 = 3773^2 + 2760^2 .

It is a cyclic number.

It is not a de Polignac number, because 21853129 - 2³ = 21853121 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21853129.

It is not a weakly prime, because it can be changed into another prime (21853121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10926564 + 10926565.

It is an arithmetic number, because the mean of its divisors is an integer number (10926565).

Almost surely, 2^21853129 is an apocalyptic number.

It is an amenable number.

21853129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21853129 is an equidigital number, since it uses as much as digits as its factorization.

21853129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 31.

The square root of 21853129 is about 4674.7330405062. The cubic root of 21853129 is about 279.5789974079.

The spelling of 21853129 in words is "twenty-one million, eight hundred fifty-three thousand, one hundred twenty-nine".