21061129 has 2 divisors, whose sum is σ = 21061130. Its totient is φ = 21061128.

The previous prime is 21061127. The next prime is 21061153. The reversal of 21061129 is 92116012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17239104 + 3822025 = 4152^2 + 1955^2 .

It is a cyclic number.

It is not a de Polignac number, because 21061129 - 2¹ = 21061127 is a prime.

Together with 21061127, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21061127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10530564 + 10530565.

It is an arithmetic number, because the mean of its divisors is an integer number (10530565).

Almost surely, 2^21061129 is an apocalyptic number.

It is an amenable number.

21061129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21061129 is an equidigital number, since it uses as much as digits as its factorization.

21061129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 21061129 is about 4589.2405689831. The cubic root of 21061129 is about 276.1598571595.

The spelling of 21061129 in words is "twenty-one million, sixty-one thousand, one hundred twenty-nine".