21424757129 has 2 divisors, whose sum is σ = 21424757130. Its totient is φ = 21424757128.

The previous prime is 21424757113. The next prime is 21424757177. The reversal of 21424757129 is 92175742412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14525793529 + 6898963600 = 120523^2 + 83060^2 .

It is a cyclic number.

It is not a de Polignac number, because 21424757129 - 2⁴ = 21424757113 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21424757129.

It is not a weakly prime, because it can be changed into another prime (21424757329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712378564 + 10712378565.

It is an arithmetic number, because the mean of its divisors is an integer number (10712378565).

Almost surely, 2^21424757129 is an apocalyptic number.

It is an amenable number.

21424757129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21424757129 is an equidigital number, since it uses as much as digits as its factorization.

21424757129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 282240, while the sum is 44.

The spelling of 21424757129 in words is "twenty-one billion, four hundred twenty-four million, seven hundred fifty-seven thousand, one hundred twenty-nine".