20645413 has 2 divisors, whose sum is σ = 20645414. Its totient is φ = 20645412.

The previous prime is 20645407. The next prime is 20645441. The reversal of 20645413 is 31454602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10647169 + 9998244 = 3263^2 + 3162^2 .

It is a cyclic number.

It is not a de Polignac number, because 20645413 - 2¹⁷ = 20514341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20645453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322706 + 10322707.

It is an arithmetic number, because the mean of its divisors is an integer number (10322707).

Almost surely, 2^20645413 is an apocalyptic number.

It is an amenable number.

20645413 is a deficient number, since it is larger than the sum of its proper divisors (1).

20645413 is an equidigital number, since it uses as much as digits as its factorization.

20645413 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 20645413 is about 4543.7223726808. The cubic root of 20645413 is about 274.3307716132.

It can be divided in two parts, 20645 and 413, that multiplied together give a triangular number (8526385 = T₄₁₂₉).

The spelling of 20645413 in words is "twenty million, six hundred forty-five thousand, four hundred thirteen".