20815453 has 2 divisors, whose sum is σ = 20815454. Its totient is φ = 20815452.

The previous prime is 20815451. The next prime is 20815481. The reversal of 20815453 is 35451802.

It is an a-pointer prime, because the next prime (20815481) can be obtained adding 20815453 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20403289 + 412164 = 4517^2 + 642^2 .

It is a cyclic number.

It is not a de Polignac number, because 20815453 - 2¹ = 20815451 is a prime.

Together with 20815451, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20815451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10407726 + 10407727.

It is an arithmetic number, because the mean of its divisors is an integer number (10407727).

Almost surely, 2^20815453 is an apocalyptic number.

It is an amenable number.

20815453 is a deficient number, since it is larger than the sum of its proper divisors (1).

20815453 is an equidigital number, since it uses as much as digits as its factorization.

20815453 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 20815453 is about 4562.3955330506. The cubic root of 20815453 is about 275.0818621302.

The spelling of 20815453 in words is "twenty million, eight hundred fifteen thousand, four hundred fifty-three".