23129521 has 2 divisors, whose sum is σ = 23129522. Its totient is φ = 23129520.

The previous prime is 23129507. The next prime is 23129531. The reversal of 23129521 is 12592132.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22667121 + 462400 = 4761^2 + 680^2 .

It is a cyclic number.

It is not a de Polignac number, because 23129521 - 2⁵ = 23129489 is a prime.

It is not a weakly prime, because it can be changed into another prime (23129531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11564760 + 11564761.

It is an arithmetic number, because the mean of its divisors is an integer number (11564761).

Almost surely, 2^23129521 is an apocalyptic number.

It is an amenable number.

23129521 is a deficient number, since it is larger than the sum of its proper divisors (1).

23129521 is an equidigital number, since it uses as much as digits as its factorization.

23129521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080, while the sum is 25.

The square root of 23129521 is about 4809.3160636415. The cubic root of 23129521 is about 284.9195258581.

The spelling of 23129521 in words is "twenty-three million, one hundred twenty-nine thousand, five hundred twenty-one".