20624239 has 2 divisors, whose sum is σ = 20624240. Its totient is φ = 20624238.

The previous prime is 20624209. The next prime is 20624251. The reversal of 20624239 is 93242602.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20624239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20624209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10312119 + 10312120.

It is an arithmetic number, because the mean of its divisors is an integer number (10312120).

Almost surely, 2^20624239 is an apocalyptic number.

20624239 is a deficient number, since it is larger than the sum of its proper divisors (1).

20624239 is an equidigital number, since it uses as much as digits as its factorization.

20624239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 20624239 is about 4541.3917470309. The cubic root of 20624239 is about 274.2369547011.

The spelling of 20624239 in words is "twenty million, six hundred twenty-four thousand, two hundred thirty-nine".