20625439 has 2 divisors, whose sum is σ = 20625440. Its totient is φ = 20625438.

The previous prime is 20625421. The next prime is 20625491. The reversal of 20625439 is 93452602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20625439 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20625439.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20625499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10312719 + 10312720.

It is an arithmetic number, because the mean of its divisors is an integer number (10312720).

Almost surely, 2^20625439 is an apocalyptic number.

20625439 is a deficient number, since it is larger than the sum of its proper divisors (1).

20625439 is an equidigital number, since it uses as much as digits as its factorization.

20625439 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 20625439 is about 4541.5238631983. The cubic root of 20625439 is about 274.2422733291.

The spelling of 20625439 in words is "twenty million, six hundred twenty-five thousand, four hundred thirty-nine".