21422129 has 2 divisors, whose sum is σ = 21422130. Its totient is φ = 21422128.

The previous prime is 21422119. The next prime is 21422143. The reversal of 21422129 is 92122412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21298225 + 123904 = 4615^2 + 352^2 .

It is a cyclic number.

It is not a de Polignac number, because 21422129 - 2¹⁶ = 21356593 is a prime.

It is a super-2 number, since 2×21422129² = 917815221785282, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21422119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711064 + 10711065.

It is an arithmetic number, because the mean of its divisors is an integer number (10711065).

Almost surely, 2^21422129 is an apocalyptic number.

It is an amenable number.

21422129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21422129 is an equidigital number, since it uses as much as digits as its factorization.

21422129 is an evil number, because the sum of its binary digits is even.

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

The square root of 21422129 is about 4628.4045847354. The cubic root of 21422129 is about 277.7287738207.

The spelling of 21422129 in words is "twenty-one million, four hundred twenty-two thousand, one hundred twenty-nine".